The Fetchmail FAQ
Description: Frequently asked questions about fetchmail.
Keywords: fetchmail, POP, POP2, POP3, IMAP, remote mail

Back to Fetchmail Home Page | To Site Map | $Date: 2000/03/04 00:13:09 $

# Frequently Asked Questions About Fetchmail

Before reporting any bug, please read G3 for advice on how to include diagnostic information that will get your bug fixed as quickly as possible.

If you have a question or answer you think ought to be added to this FAQ list, mail it to fetchmail's maintainer, Eric S. Raymond, at esr@snark.thyrsus.com.

# General questions:

G1. What is fetchmail and why should I bother?
G2. Where do I find the latest FAQ and fetchmail sources?
G3. I think I've found a bug. Will you fix it?
G4. I have this idea for a neat feature. Will you add it?
G5. Is there a mailing list for exchanging tips?
G6. So, what's this I hear about a fetchmail paper?
G7. What is the best server to use with fetchmail?
G8. What is the best mail program to use with fetchmail?
G9. How can I avoid sending my password en clair?
G10. Is any special configuration needed to use a dynamic IP address?
G11. Is any special configuration needed to use firewalls?
G12. Is any special configuration needed to send mail?
G13. Is fetchmail Y2K-compliant?
G14. Is there a way in fetchmail to support disconnected IMAP mode?

# Build-time problems:

B1. Lex bombs out while building the fetchmail lexer.
B2. I get link failures when I try to build fetchmail.

# Fetchmail configuration file grammar questions:

F1. Why does my old .fetchmailrc no longer work?
F2. The .fetchmailrc parser won't accept my all-numeric user name.
F3. The .fetchmailrc parser won't accept my host or username beginning with `no'.
F4. I'm getting a `parse error' message I don't understand.

# Configuration questions:

C1. Why do I need a .fetchmailrc when running as root on my own machine?
C2. How can I arrange for a fetchmail daemon to get killed when I log out?
C3. How do I know what interface and address to use with --interface?
C4. How can I set up support for sendmail's anti-spam features?
C5. How can I poll some of my mailboxes more/less often than others?
C6. Fetchmail works OK started up manually, but not from an init script.
C7. How can I forward mail to another host?.

# How to make fetchmail play nice with various MTAs:

T1. How can I use fetchmail with sendmail?
T2. How can I use fetchmail with qmail?
T3. How can I use fetchmail with exim?
T4. How can I use fetchmail with smail?
T5. How can I use fetchmail with SCO's MMDF?
T6. How can I use fetchmail with Lotus Notes?

# How to make fetchmail work with various servers:

S1. How can I use fetchmail with qpopper?
S2. How can I use fetchmail with Microsoft Exchange?
S3. How can I use fetchmail with Compuserve RPA?
S4. How can I use fetchmail with Demon Internet's SDPS?
S5. How can I use fetchmail with usa.net's servers?
S6. How can I use fetchmail with HP OpenMail?
S7. How can I use fetchmail with geocities POP3 servers?
S8. How can I use fetchmail with Hotmail?
S9. How can I use fetchmail with MSN?
S10. How can I use fetchmail with SpryNet?
S11. How can I use fetchmail with FTGate?
S12. How can I use fetchmail with MailMax?
S13. How can I use fetchmail with Novell GroupWise?
S14. How can I use fetchmail with InterChange?

# How to set up well-known security and authentication methods:

K1. How can I use fetchmail with SOCKS?
K2. How can I use fetchmail with IPv6 and IPsec?
K3. How can I get fetchmail to work with ssh?
K4. What do I have to do to use the IMAP-GSS protocol?
K5. How can I use fetchmail with SSL?

# Runtime fatal errors:

R1. Fetchmail isn't working, and -v shows `SMTP connect failed' messages.
R2. When I try to configure an MDA, fetchmail doesn't work.
R3. Fetchmail dumps core when given an invalid rc file.
R4. Fetchmail dumps core in -V mode, but operates normally otherwise.
R5. Running fetchmail in daemon mode doesn't work.
R6. Fetchmail hangs when used with pppd.
R7. Fetchmail randomly dies with socket errors.
R8. Fetchmail running as root stopped working after an OS upgrade
R9. Fetchmail is timing out after fetching certain messages but before deleting them
R10. Fetchmail is timing out during message fetches

# Disappearing mail

D1. I think I've set up fetchmail correctly, but I'm not getting any mail.
D2. All my mail seems to disappear after a dropped connection.
D3. Mail that was being fetched when I interrupted my fetchmail seems to have been vanished.

# Multidrop-mode problems:

M1. I've declared local names, but all my multidrop mail is going to root anyway.
M2. I can't seem to get fetchmail to route to a local domain properly.
M3. I tried to run a mailing list using multidrop, and I have a mail loop!
M4. My multidrop fetchmail seems to be having DNS problems.
M5. I'm seeing long DNS delays before each message is processed.
M6. How do I get multidrop mode to work with majordomo?
M7. Multidrop mode isn't parsing envelope addresses from my Received headers as it should.
M8. Users are getting multiple copies of messages.

# Mangled mail:

X1. Spurious blank lines are appearing in the headers of fetched mail.
X2. My mail client can't see a Subject line.
X3. Messages containing "From" at start of line are being split.
X4. My mail is being mangled in a new and different way.
X5. Using POP3, retrievals seems to be fetching too much!

# Other problems:

O1. The --logfile option doesn't work if the logfile doesn't exist.
O2. Every time I get a POP or IMAP message the header is dumped to all my terminal sessions.
O3. Does fetchmail reread its rc file every poll cycle?
O4. Why do deleted messages show up again when I take a line hit while downloading?
O5. Why is fetched mail being logged with my name, not the real From address?
O6. I'm seeing long sendmail delays or hangs near the start of each poll cycle.
O7. Why doesn't fetchmail deliver mail in date-sorted order?
O8. I'm using pppd. Why isn't my monitor option working?
O9. Why does fetchmail keep retrieving the same messages over and over?

# Answers:

## G1. What is fetchmail and why should I bother?

Fetchmail is a one-stop solution to the remote mail retrieval problem for Unix machines, quite useful to anyone with an intermittent PPP or SLIP connection to a remote mailserver. It can collect mail using any variant of POP or IMAP and forwards via port 25 to the local SMTP listener, enabling all the normal forwarding/filtering/aliasing mechanisms that would apply to local mail or mail arriving via a full-time TCP/IP connection.

Fetchmail is not a toy or a coder's learning exercise, but an industrial-strength tool capable of transparently handling every retrieval demand from those of a simple single-user ISP connection up to mail retrieval and rerouting for an entire client domain. Fetchmail is easy to configure, unobtrusive in operation, powerful, feature-rich, and well documented.

Fetchmail is Open Source software. The openness of the sources is the strongest assurance of quality you can have. Extensive peer review by a large, multi-platform user community has shown that fetchmail is as near bulletproof as the underlying protocols permit.

Fetchmail is licensed under the GNU General Public License.

If you found this FAQ in the distribution, see the README for fetchmail's full feature list.

## G2. Where do I find the latest FAQ and fetchmail sources?

The latest HTML FAQ is available alongside the latest fetchmail sources at the fetchmail home page: http://www.tuxedo.org/~esr/fetchmail. You can also usually find both in the POP mail tools directory on Sunsite.

A text dump of this FAQ is included in the fetchmail distribution. Because it freezes at distribution release time, it may not be completely current.

## G3. I think I've found a bug. Will you fix it?

Yes I will, provided you include enough diagnostic information for me to go on. Send bugs to fetchmail-friends. When reporting bugs, please include the following:

1. Your operating system and compiler version.
2. A copy of your POP or IMAP server's greeting line.
3. The name and version of the SMTP listener or MDA you are forwarding to.
4. Any command-line options you used.
5. The output of fetchmail -V called with whatever other command-line options you used.

If you have FTP access to your remote mail account, and you have any suspicion that the bug was triggered by a particular message, please include a copy of the message that triggered the bug.

Often, the first thing I will do when you report a bug is tell you to upgrade to the newest version of fetchmail, and then see if the problem reproduces. So you'll probably save us both time if you upgrade and test with the latest version before sending in a bug report.

It is helpful if you include your .fetchmailrc file, but not necessary unless your symptom seems to involve an error in configuration parsing. If you do send in your .fetchmailrc, mask the passwords first!

If fetchmail seems to run and fetch mail, but the headers look mangled (that is, headers are missing or blank lines are inserted in the headers) then read the FAQ items in section X before submitting a bug report. Pay special attention to the item on diagnosing mail mangling. There are lots of ways for other programs in the mail chain to screw up that look like fetchmail's fault, but you may be able to fix these by tweaking your configuration.

A transcript of the failed session with -v -v (yes, that's two -v options, enabling debug mode) will almost always be useful. It is very important that the transcript include your POP/IMAP server's greeting line, so I can identify it in case of server problems. This transcript will not reveal your passwords, which are specially masked out precisely so the transcript can be passed around.

If the bug involves a core dump or hang, a gdb stack trace is good to have. (Bear in mind that you can attach gdb to a running but hung process by giving the process ID as a second argument.) You will need to reconfigure with

    CFLAGS=-g LDFLAGS=" " ./configure

and then rebuild in order to generate a version that can be gdb-traced.

Best of all is a mail file which, when fetched, will reproduce the bug under the latest (current) version.

Any bug I can reproduce will usually get fixed very quickly, often within 48 hours. Bugs I can't reproduce are a crapshoot. If the solution isn't obvious when I first look, it may evade me for a long time (or to put it another way, fetchmail is well enough tested that the easy bugs have long since been found). So if you want your bug fixed rapidly, it is not just sufficient but nearly necessary that you give me a way to reproduce it.

## G4. I have this idea for a neat feature. Will you add it?

Probably not. Most of the feature suggestions I get are for ways to set various kinds of administrative policy or add more spam filtering (the most common one, which I used to get about four million times a week and got really tired of, is for tin-like kill files).

You can do spam filtering better with procmail or maildrop on the server side and (if you're the server sysadmin) sendmail.cf domain exclusions. You can do other policy things better with the `mda` option and script wrappers around fetchmail. If it's a prime-time-vs.-non-prime-time issue, ask yourself whether a wrapper script called from crontab would do the job.

I'm not going to do these; fetchmail's job is transport, not policy, and I refuse to change it from doing one thing well to attempting many things badly. One of my objectives is to keep fetchmail simple so it stays reliable.

For reasons fetchmail doesn't have other commonly-requested features (such as password encryption, or multiple concurrent polls from the same instance of fetchmail) see the design notes.

Fetchmail is a mature project, no longer in constant active development. It is no longer my top project, and I am going to be quite reluctant to add features that might either jeopardize its stability or involve me in large amounts of coding.

All that said, if you have a feature idea that really is about a transport problem that can't be handled anywhere but fetchmail, lay it on me. I'm very accommodating about good ideas.

## G5. Is there a mailing list for exchanging tips?

There is a fetchmail-friends list for people who want to discuss fixes and improvements in fetchmail and help co-develop it. It's at fetchmail-friends@thyrsus.com. There is also an announcements-only list, fetchmail-announce@thyrsus.com.

Both lists are SmartList reflectors; sign up in the usual way with a message containing the word "subscribe" in the subject line sent to fetchmail-friends-request@thyrsus.com or fetchmail-announce-request@thyrsus.com. (Similarly, "unsubscribe" in the Subject line unsubscribes you, and "help" returns general list help)

## G6. So, what's this I hear about a fetchmail paper?

The fetchmail development was also a sociological experiment, an extended test to see if my theory about the critical features of the Linux development model is correct.

The experiment was a success. I wrote a paper about it titled The Cathedral and the Bazaar which was first presented at Linux Kongress '97 in Bavaria and very well received there. It was also given at Atlanta Linux Expo, Linux Pro '97 in Warsaw, and the first Perl Conference, at UniForum '98, and was the basis of an invited presentation at Usenix '98. The folks at Netscape tell me it helped them decide to give away the source for Netscape Communicator.

If you're reading a non-HTML dump of this FAQ, you can find the paper on the Web with a search for that title.

## G7. What is the best server to use with fetchmail?

The short answer: IMAP4rev1 running over Unix.

Here's a longer answer:

Fetchmail will work with any POP, IMAP, or ESMTP/ETRN server that conforms to the relevant RFCs (and even some outright broken ones like Microsoft Exchange and Novell GroupWise). This doesn't mean it works equally well with all, however. POP2 servers, and POP3 servers without LAST, limit fetchmail's capabilities in various ways described on the manual page.

Most modern Unixes (and effectively all Linux/*BSD systems) come with POP3 support preconfigured (but beware of the horribly broken POP3 server mentioned in D2). An increasing minority also feature IMAP (you can detect IMAP support by running fetchmail in AUTO mode, or by using the `Probe for supported protocols' function in the fetchmailconf utility).

If you have the option, we recommend using or installing an IMAP4rev1 server; it has the best facilities for tracking message `seen' states. It also recovers from interrupted connections more gracefully than POP3, and enables some significant performance optimizations.

Don't be fooled by NT/Exchange propaganda. M$ Exchange is just plain broken (see item S2) and NT cannot handle the sustained load of a high-volume remote mail server. Even Microsoft itself knows better than to try this; their own Hotmail service runs over Solaris! For extended discussion, see John Kirch's excellent white paper on Unix vs. NT performance.

You can find sources for IMAP software at The IMAP Connection; we like the open-source UW IMAP server, which is the reference implementation of IMAP. UW IMAP's support for GSSAPI gives you a good way to authenticate without sending a password en clair.

Source for a high-quality supported implementation of POP is available from the Eudora FTP site. Don't use 2.5, which has a rather restrictive license. The 2.5.2 version appears to restore the open-source license of previous versions.

## G8. What is the best mail program to use with fetchmail?

Fetchmail will work with all popular mail transport programs. It also doesn't care which user agent you use, and user agents are as a rule almost equally indifferent to how mail is delivered into your system mailbox. So any of the popular Unix mail agents -- elm, pine mh, or mutt -- will work fine with fetchmail.

All this having been said, I can't resist putting in a discreet plug for mutt. My own personal mail setup is sendmail plus fetchmail plus mutt. Mutt's interface is only a little different from that of its now-moribund ancestor elm, but its excellent handling of MIME and PGP put it in a class by itself. You won't need its built-in POP3 support, though; most of the mutt developers will cheerfully admit that fetchmail's is better :-).

## G9. How can I avoid sending my password en clair?

Depending on what your mail server you are talking to, this ranges from trivial to impossible. It may even be next to useless.

Most people use fetchmail over phone wires, which are hard to tap. Anybody with the skill and resources to do this could get into your server mailbox with much less effort by subverting the server host. So if your provider setup is modem wires going straight into a service box, you probably don't need to worry.

In general there is little point in trying to secure your fetchmail transaction unless you trust the security of the server host you are retrieving mail from. Your vulnerability is more likely to be an insecure local network on the server end (e.g. to somebody with a TCP/IP packet sniffer intercepting Ethernet traffic between the modem concentrator you dial in to and the mailserver host).

Having realized this, you need to ask whether password encryption alone will really address your security exposure. If you think you might be snooped between server and client, it's better to use end-to-end encryption on your whole mail stream so none of it can be read. One of the advantages of fetchmail over conventional SMTP-push delivery is that you may be able to arrange this by using ssh(1); see K3.

Note that ssh is not a complete privacy solution either, as your mail could have been snooped in transit to your POP server from wherever it originated. For best security, agree with your correspondents to use a tool such as GPG (Gnu Privacy Guard) or PGP (Pretty Good Privacy).

If ssh/sshd isn't available, or you find it too complicated for you to set up, password encryption will at least keep a malicious cracker from deleting your mail, and require him to either tap your connection continuously or crack root on the server in order to read it.

You can deduce what encryptions your mail server has available by looking at the server greeting line (and, for IMAP, the response to a CAPABILITY query). Do a `fetchmail -v` to see these, or telnet direct to the server port (110 for POP3, 143 for IMAP).

The facility you are most likely to have available is APOP. This is a POP3 feature supported by many servers (fetchmailconf's autoprobe facility will detect it and tell you if you have it). If you see something in the greeting line that looks like an angle-bracket-enclosed Internet address with a numeric left-hand part, that's an APOP challenge (it will vary each time you log in). You can register a secret on the host (using `popauth(8)` or some program like it). Specify the secret as your password in your .fetchmailrc; it will be used to encrypt the current challenge, and the encrypted form will be sent back the the server for verification.

Alternatively, you may have Kerberos available. This may require you to set up some magic files in your home directory on your client machine, but means you can omit specifying any password at all.

Fetchmail supports two different Kerberos schemes. One is a POP3 variant called KPOP; consult the documentation of your mail server to see if you have it (one clue is the string "krb-IV" in the greeting line on port 110). The other is an IMAP facility described by RFC1731. You can tell if this one is present by looking for AUTH=KERBEROS_V4 in the CAPABILITY response.

If you are fetching mail from a CompuServe POP3 account, you can use their RPA authentication (which works much like APOP). See S3 for details. If you are fetching mail from Microsoft Exchange, you will be able to use NTLM.

Your POP3 server may have the RFC1938 OTP capability to use one-time passwords (if it doesn't, you can get OTP patches for the 2.2 version of the Qualcomm popper from Craig Metz). To check this, look for the string "otp-" in the greeting line. If you see it, and your fetchmail was built with OPIE support compiled in (see the distribution INSTALL file), fetchmail will detect it also. When using OTP, you will specify a password but it will not be sent en clair.

Sadly, there is at present (September 1999) no OTP or APOP-like facility generally available on IMAP servers. However, there do exist patches which will OTP-enable the University of Washington IMAP daemon, version 4.2-FINAL. We have a report that the GSSAPI support in fetchmail works with the GSSAPI support in the most recent version of UW IMAP. Or you can use SSL for complete end-to-end encryption if you have an SSL-enabled mailserver.

You can get both POP3 and IMAP OTP patches from Craig Metz at http://www.inner.net/pub/.

These patches use a SASL authentication method named "X-OTP" because there is not currently a standard way to do this; fetchmail also uses this method, so the two will interoperate happily. They better, because this is how Craig gets his mail ;-)

(One important win of OTP is that it's not subject to U.S. export restrictions.)

## G10. Is any special configuration needed to use a dynamic IP address?

Yes. In order to avoid giving indigestion to certain picky MTAs (notably exim), fetchmail always makes the RCPT TO address it feeds the MTA a fully qualified one with a hostname part. Normally it does this by appending @ and "localhost", but when you are using Kerberos or ETRN mode it will append @ and your machine's fully-qualified domain name (FQDN).

Appending the FQDN can create problems when fetchmail is running in daemon mode and outlasts the dynamic IP address assignment your client machine had when it started up.

Since the new IP address (looked up at RCPT TO interpretation time) doesn't match the original, the most benign possible result is that your MTA thinks it's seeing a relaying attempt and refuses. More frequently, fetchmail will try to connect to a nonexistent host address and time out. Worst case, you could up forwarding your mail to the wrong machine!

Use the `smtpaddress` option to force the appended hostname to one with a (fixed) IP address of 127.0.0.1 in your `/etc/hosts`. (The name `localhost' will usually work; or you can use the IP address itself).

Only one fetchmail option interacts directly with your IP address, ``interface`'. This option can be used to set the gateway device and restrict the IP address range fetchmail will use. Such a restriction is sometimes useful for security reasons, especially on multihomed sites. See C3.

I recommend against trying to set up the `interface` option when initially developing your poll configuration -- it's never necessary to do this just to get a link working. Get the link working first, observe the actual address range you see on connections, and add an `interface` option (if you need one) later.

If you're using a dynamic-IP configuration, one other (non-fetchmail) problem you may run into with outgoing mail is that some sites will bounce your email because the hostname your giving them isn't real (and doesn't match what they get doing a reverse DNS on your dynamically-assigned IP address). If this happens, you need to hack your sendmail so it masquerades as your host. Setting

    DMsmarthost.here

in your `sendmail.cf` will work, or you can set

    MASQUERADE_AS(smarthost.here)

in the m4 configuration and do a reconfigure. (In both cases, replace `smarthost.here` with the actual name of your mailhost.) See the sendmail FAQ for more details.

## G11. Is any special configuration needed to use firewalls?

No. You can use fetchmail with SOCKS, the standard tool for indirecting TCP/IP through a firewall. You can find out about SOCKS, and download the SOCKS software including server and client code, at the SOCKS distribution site.

The specific recipe for using fetchmail with a firewall is at K1

## G12. Is any special configuration needed to send mail?

A user asks: but how do we send mail out to the POP3 server? Do I need to implement another tool or will fetchmail do this too?

Fetchmail only handles the receiving side. The sendmail or other preinstalled MTA on your client machine will handle sending mail automatically; it will ship mail that is submitted while the connection is active, and put mail that is submitted while the connection is inactive into the outgoing queue.

Normally, sendmail is also run periodically (every 15 minutes on most Linux systems) in a mode that tries to ship all the mail in the outgoing queue. If you have set up something like pppd to automatically dial out when your kernel is called to open a TCP/IP connection, this will ensure that the mail gets out.

## G13. Is fetchmail Y2K-compliant?

Fetchmail is fully Y2K-compliant.

Fetchmail could theoretically have problems when the 32-bit time_t counters roll over in 2038, but I doubt it. Timestamps aren't used for anything but log entry generation. Anyway, if you aren't running on a 64-bit machine by then, you deserve to lose.

## G14. Is there a way in fetchmail to support disconnected IMAP mode?

No. Fetchmail is a mail transport agent, best understood as a protocol gateway between POP3/IMAP servers and SMTP. Disconnected operation requires an elaborate interactive client. It's a very different problem.

## B1. Lex bombs out while building the fetchmail lexer.

In the immortal words of Alan Cox the last time this came up: ``Take the Solaris lex and stick it up the backside of a passing Sun salesman, then install flex and use that. All will be happier.''

I couldn't have put it better myself, and ain't going to try now.

## B2. I get link failures when I try to build fetchmail.

If you get errors resembling these

    mxget.o(.text+0x35): undefined referenceto `__res_search'
    mxget.o(.text+0x99): undefined reference to`__dn_skipname'
    mxget.o(.text+0x11c): undefined reference to`__dn_expand'
    mxget.o(.text+0x187): undefined reference to`__dn_expand'
    make: *** [fetchmail] Error 1

then you must add "-lresolv" to the LOADLIBS line in your Makefile once you have installed the `bind' package.

## F1. Why does my old .fetchmailrc file no longer work?

### If your file predates 5.1.0

In 5.1.0, the `auth` keyword and option were changed to `preauth`.

### If your file predates 4.5.5

If the `dns` option is on (the default), you may need to make sure that any hostname you specify (for mail hosts or for an SMTP target) is a canonical fully-qualified hostname). In order to avoid DNS overhead and complications, fetchmail no longer tries to derive the fetchmail client machine's canonical DNS name at startup.

### If your file predates 4.0.6:

Just after the ``via`' option was introduced, I realized that the interactions between the ``via`', ``aka`', and ``localdomains`' options were out of control. Their behavior had become complex and confusing, so much so that I was no longer sure I understood it myself. Users were being unpleasantly surprised.

Rather than add more options or crock the code, I re-thought it. The redesign simplified the code and made the options more orthogonal, but may have broken some complex multidrop configurations. Any multidrop configurations that depended on the name just after the ``poll`' or ``skip`' keyword being still interpreted as a DNS name for address-matching purposes, even in the presence of a ``via`' option, will break.

It is theoretically possible that other unusual configurations (such as those using a non-FQDN poll name to generate Kerberos IV tickets) might also break; the old behavior was sufficiently murky that we can't be sure. If you think this has happened to you, contact the maintainer.

### If your file predates 3.9.5:

The ``remote`' keyword has been changed to ``folder`'. If you try to use the old keyword, the parser will utter a warning.

### If your file predates 3.9:

It could be because you're using a .fetchmailrc that's written in the old popclient syntax without an explicit ``username`' keyword leading the first user entry attached to a server entry. This error can be triggered by having a user option such as ``keep`' or ``fetchall`' before the first explicit username. For example, if you write

    poll openmail protocol pop3
    	keep user "Hal DeVore" there is hdevore here

the ``keep`' option will generate an entire user entry with the default username (the name of fetchmail's invoking user).

The popclient compatibility syntax was removed in 4.0. It complicated the configuration file grammar and confused users.

### If your file predates 2.8:

The ``interface`', ``monitor`' and ``batchlimit`' options changed after 2.8.

They used to be global options with ``set`' syntax like the batchlimit and logfile options. Now they're per-server options, like ``protocol`'.

If you had something like

    	set interface = "sl0/10.0.2.15"

in your .fetchmailrc file, simply delete that line and insert `interface sl0/10.0.2.15' in the server options part of your `defaults' declaration.

Do similarly for any ``monitor`' or ``batchlimit`' options.

## F2. The .fetchmailrc parser won't accept my all-numeric user name.

Either upgrade to a post-5.0.5 fetchmail or put string quotes around it. :-)

The configuration file parser in older fetchmail versions treated any all-numeric token as a number, which confused it when it was expecting a name. String quoting forces the token's class.

The lexical analyzer in 5.0.6 and beyond is smarter and assumes any token following "username" or "password" is a string.

## F3. The .fetchmailrc parser won't accept my host or username beginning with `no'.

See F2 You're caught in an unfortunate crack between the newer-style syntax for negated options (`no keep', `no rewrite' etc.) and the older style run-on syntax (`nokeep', `norewrite' etc.).

Upgrade to a 5.0.6 or later fetchmail, or put string quotes around your token.

## F4. I'm getting a `parse error' message I don't understand.

The most common cause of mysterious parse errors is putting a server option after a user option. Check the manual page; you'll probably find that by moving one or more options closer to the `poll' keyword you can eliminate the problem.

Yes, I know these ordering restrictions are hard to understand. Unfortunately, they're necessary in order to allow the `defaults' feature to work.

## C1. Why do I need a .fetchmailrc when running as root on my own machine?

Ian T. Zimmerman <itz@rahul.net> asked:

On the machine where I'm the only real user, I run fetchmail as root from a cron job, like this:

        fetchmail -u "itz" -p POP3 -s bolero.rahul.net

This used to work as is (with no .fetchmailrc file in root's home directory) with the last version I had (1.7 or 1.8, I don't remember). But with 2.0, it RECPs all mail to the local root user, unless I create a .fetchmailrc in root's home directory containing:

         skip bolero.rahul.net proto POP3
              user itz is itz

It won't work if the second line is just "`user itz`". This is silly.

It seems fetchmail decides to RECP the `default local user' (i.e. the uid running fetchmail) unless there are local aliases, and the `default' aliases (itz->itz) don't count. They should.

Answer:

No they shouldn't. I thought about this for a while, and I don't much like the conclusion I reached, but it's unavoidable. The problem is that fetchmail has no way to know, in general, that a local user `itz' actually exists.

"Ah!" you say, "Why doesn't it check the password file to see if the remote name matches a local one?" Well, there are two reasons.

One: it's not always possible. Suppose you have an SMTP host declared that's not the machine fetchmail is running on? You lose.

Two: How do you know server itz and SMTP-host itz are the same person? They might not be, and fetchmail shouldn't assume they are unless local-itz can explicitly produce credentials to prove it (that is, the server-itz password in local-itz's .fetchmailrc file.).

Once you start running down possible failure modes and thinking about ways to tinker with the mapping rules, you'll quickly find that all the alternatives to the present default are worse or unacceptably more complicated or both.

## C2. How can I arrange for a fetchmail daemon to get killed when I log out?

The easiest way to dispatch fetchmail on logout (which will work reliably only if you have just one login going at any time) is to arrange for the command `fetchmail -q' to be called on logout. Under bash, you can arrange this by putting `fetchmail -q' in the file `~/.bash_logout'. Most csh variants execute `~/.logout' on logout. For other shells, consult your shell manual page.

Automatic startup/shutdown of fetchmail is a little harder to arrange if you may have multiple login sessions going. In the contrib subdirectory of the fetchmail distribution there is some shell code you can add to your .bash_login and .bash_logout profiles that will accomplish this. Thank James Laferriere <babydr@nwrain.net> for it.

Some people start up and shut down fetchmail using the ppp-up and ppp-down scripts of pppd.

## C3. How do I know what interface and address to use with --interface?

This depends a lot on your local networking configuration (and right now you can't use it at all except under Linux and the newer BSDs). However, here are some important rules of thumb that can help. If they don't work, ask your local sysop or your Internet provider.

First, you may not need to use --interface at all. If your machine only ever does SLIP or PPP to one provider, it's almost certainly by a point to point modem connection to your provider's local subnet that's pretty secure against snooping (unless someone can tap your phone or the provider's local subnet!). Under these circumstances, specifying an interface address is fairly pointless.

What the option is really for is sites that use more than one provider. Under these circumstances, typically one of your provider IP addresses is your mailserver (reachable fairly securely via the modem and provider's subnet) but the others might ship your packets (including your password) over unknown portions of the general Internet that could be vulnerable to snooping. What you'll use --interface for is to make sure your password only goes over the one secure link.

To determine the device:

1. If you're using a SLIP link, the correct device is probably sl0.
2. If you're using a PPP link, the correct device is probably ppp0.
3. If you're using a direct connection over a local network such as an ethernet, use the command `netstat -r' to look at your routing table. Try to match your mailserver name to a destination entry; if you don't see it in the first column, use the `default' entry. The device name will be in the rightmost column.

To determine the address and netmask:

1. If you're talking to slirp, the correct address is probably 10.0.2.15, with no netmask specified. (It's possible to configure slirp to present other addresses, but that's the default.)
2. If you have a static IP address, run `ifconfig <device>', where <device> is whichever one you've determined. Use the IP address given after "inet addr:". That is the IP address for your end of the link, and is what you need. You won't need to specify a netmask.
3. If you have a dynamic IP address, your connection IP will vary randomly over some given range (that is, some number of the least significant bits change from connection to connection). You need to declare an address with the variable bits zero and a complementary netmask that sets the range.

To illustrate the rule for dynamic IP addresses, let's suppose you're hooked up via SLIP and your IP provider tells you that the dynamic address pool is 255 addresses ranging from 205.164.136.1 to 205.164.136.255. Then

    	interface "sl0/205.164.136.0/255.255.255.0"

would work. To range over any value of the last two octets (65536 addresses) you would use

    	interface "sl0/205.164.0.0/255.255.0.0"

## C4. How can I set up support for sendmail's anti-spam features?

This answer covers versions of sendmail from 8.8.7 (the version installed in Red Hat 5.1) upwards. If you have an older version, upgrade to sendmail 8.9.

Stock sendmails can now do anti-spam exclusions based on a database of filter rules. The human-readable form of the database is at `/etc/mail/deny`. The database itself is at `/etc/mail/deny.db`.

The table itself uses email addresses, domain names, and network numbers as keys. For example,

    spammer@aol.com         REJECT
    cyberspammer.com        REJECT
    192.168.212             REJECT

would refuse mail from spammer@aol.com, any user from cyberspammer.com (or any host within the cyberspammer.com domain), and any host on the 192.168.212.* network. (This feature can be used to do other things as well; see the sendmail documentation for details)

To actually set up the database, run

    makemap hash deny <deny

in /etc/mail.

To test, send a message to your mailing address from that host and then pop off the message with fetchmail, using the -v argument. You can monitor the SMTP transaction, and when the FROM address is parsed, if sendmail sees that it is an address in spamlist, fetchmail will flush and delete it.

Under no circumstances put your mailhost or any host you accept mail from using fetchmail into your reject file. You will lose mail if you do this!!!

## C5. How can I poll some of my mailboxes more/less often than others?

Use the interval keyword on the ones that should be checked less often. For example, if you do a poll every 5 minutes, and want to poll some mailboxes every 5 minutes and some every 30 minutes, use something like this:

    poll mainsite.example.com  proto pop3 user ....
    poll secondary.example.com proto pop3 interval 6 user ...

Then secondary.example.com will be polled every 6th time that mainsite.example.com is polled, which with a polling interval of every 5 minutes means that secondary.example.com will be polled every 30 minutes.

## Fetchmail works OK started up manually, but not from an init script.

Often, startup scripts have a different environment than an interactive login shell. For instance, $HOME might point to "/root" when you are logged in as root, but it might be either unset, or set to "/" when the startup scripts are running. That means fetchmail at startup can't find the .fetchmailrc.

Pick a location (such as /etc/fetchmailrc) and use fetchmail's -f option to point fetchmail at it. That should solve the problem.

## C7. How can I forward mail to another host?

To forward mail to a host other than the one you are running fetchmail on, use the `smtphost` option. See the manual page for details.

## T1. How can I use fetchmail with sendmail?

For most sendmails, no special configuration is required. Eric Allman tells me that if `FEATURE(always_add_domain)` is included in sendmail's configuration, you can leave the `rewrite` option off.

If your sendmail complains ``sendmail does not relay'', make sure your sendmail,cf file says `Cwlocalhost` so that sendmail recognizes `localhost' as a name of its host.

If you're mailing from another machine on your local network, also ensure that its IP address is listed in ip_allow or name in name_allow (usually in /etc/mail/)

If you find that your sendmail doesn't like the address `FETCHMAIL-DAEMON@localhost' (which is used in the bouncemail that fetchmail generates), you may have to set `FEATURE(accept_unqualified_senders)`.

Günther Leber reports that Digital Unix sendmails won't work with fetchmail. The symptom is an error message "`553 Local configuration error, hostname not recognized as local`". The problem is that fetchmail normally feeds sendmail with the client machine's host address in the MAIL FROM line. These sendmails think this means they're seeing the result of a mail loop and suppress the mail. You may be able to work around this by running in `--invisible` mode.

If you want to support multidrop mode, and you can get access to your mailserver's sendmail.cf file, it's a good idea to add this rule:

    H?l?Delivered-To: $u

and declare ``envelope "Delivered-To:"`'. This will cause the mailserver's sendmail to reliably write the appropriate envelope address into each message before fetchmail sees it, and tell fetchmail which header it is. With this change, multidrop mode should work reliably even when the Received header omits the envelope address (which will typically be the case when the message has multiple recipients).

Martijn Lievart has a more detailed recipe in the contrib subdirectory of the fetchmail source distribution.

## T2. How can I use fetchmail with qmail?

Turn on the `forcecr` option; qmail's listener mode doesn't like header or message lines terminated with bare linefeeds.

(This information is thanks to Robert de Bath <robert@mayday.cix.co.uk>.)

If a mailhost is using the qmail package (see http://pobox.com/~djb/qmail.html) then, providing the local hosts are also using qmail, it is possible to set up one fetchmail link to be reliably collect the mail for an entire domain.

One of the basic features of qmail is the `Delivered-To:' message header. Whenever qmail delivers a message to a local mailbox it puts the username and hostname of the envelope recipient on this line. The major reason for this is to prevent mail loops.

To set up qmail to batch mail for a disconnected site the ISP-mailhost will have normally put that site in its `virtualhosts' control file so it will add a prefix to all mail addresses for this site. This results in mail sent to 'username@userhost.userdom.dom.com' having a 'Delivered-To:' line of the form:

           Delivered-To: mbox-userstr-username@userhost.userdom.dom.com

A single host maildrop will be slightly simpler:

           Delivered-To: mbox-userstr-username@userhost.dom.com

The ISP can make the 'mbox-userstr-' prefix anything they choose but a string matching the user host name is likely.

To use this line you must:

1. Ensure the option `envelope Delivered-To:' is in the fetchmail config file.
2. Ensure you have a localdomains containing 'userdom.dom.com' or `userhost.dom.com' respectively.

So far this reliably delivers messages to the correct machine of the local network, to deliver to the correct user the 'mbox-userstr-' prefix must be stripped off of the user name. This can be done by setting up an alias within the qmail MTA on each local machine. Simply create a dot-qmail file called '.qmail-mbox-userstr-default' in the alias directory (normally /var/qmail/alias) with the contents:

          | ../bin/qmail-inject -a -f"$SENDER" "${LOCAL#mbox-userstr-}@$HOST"

Note this does require a modern /bin/sh.

Peter Wilson adds:

``My ISP uses "alias-unzzippedcom-" as the prefix, which means that I need to name my file ".qmail-unzzippedcom-default". This is due to qmail's assumption that a message sent to user-xyz is handled by the file ~user/.qmail-xyz (or ~user/.qmail-default).''

Luca Olivetti adds:

If you aren't using qmail locally, or you don't want to set up the alias mechanism described above, you can use the option ``qvirtual "mbox-userstr-"`' in your fetchmail config file to strip the prefix from the local user name.

## T3. How can I use fetchmail with exim?

If you have `rewrite` on:

There is an RFC1123 requirement that MAIL FROM and RCPT TO addresses you pass to it have to be canonical (e.g. with a fully qualified hostname part). Therefore fetchmail tries to pass fully qualified RCPT TO addresses. But exim does not by default accept `localhost' as a fully qualified domain. This can be fixed.

In exim.conf, add `localhost' to your local_domains declaration if it's not already present. For example, the author's site at thyrsus.com would have a line reading:

           local_domains = thyrsus.com:localhost

If you have `rewrite` off:

MAIL FROM is a potential problem if the MTAs upstream from your fetchmail don't necessarily pass canonicalized From and Return-Path addresses, and fetchmail's `rewrite` option is off. The specific case where this has come up involves bounce messages generated by sendmail on your mailer host, which have the (un-canonicalized) origin address MAILER-DAEMON.

The right way to fix this is to enable the `rewrite` option and have fetchmail canonicalize From and Return-Path addresses with the mailserver hostname before exim sees them. This option is enabled by default, so it won't be off unless you turned it off.

If you must run with `rewrite` off, there is a switch in exim's configuration files that allows it to accept domainless MAIL FROM addresses; you will have to flip it by putting the line

            sender_unqualified_hosts = localhost

in the main section of the exim configuration file. Note that this will result in such messages having an incorrect domain name attached to their return address (your SMTP listener's hostname rather than that of the remote mail server).

## T4. How can I use fetchmail with smail?

Smail 3.2 is very nearly plug-compatible with sendmail, and may work fine out of the box.

We have one report that when processing multiple messages from a single fetchmail session, smail sometimes delivers them in an order other than received-date order. This can be annoying because it scrambles conversational threads. This is not fetchmail's problem, it is an smail `feature' and has been reported to the maintainers as a bug.

Very recent smail versions require an `-smtp_hello_verify` option in the smail config file. This overrides smail's check to see that the HELO address is actually that of the client machine, which is never going to be the case when fetchmail is in the picture. According to RFC1123 an SMTP listener must allow this mismatch, so smail's new behavior (introduced sometime between 3.2.0.90 and 3.2.0.95) is a bug.

## T5. How can I use fetchmail with SCO's MMDF?

MMDF itself is difficult to configure, but it turns out that connecting fetchmail to MMDF's SMTP channel isn't that hard. You can read an MMDF recipe that describes replacing a UUCP link with fetchmail feeding MMDF.

## T6. How can I use fetchmail with Lotus Notes?

The Lotus Notes SMTP gateway tries to deduce when it should convert \n to \r\n, but its rules are not the intuitive and correct-for-RFC822 ones. Use `forcecr'.

## S1. How can I use fetchmail with qpopper?

Qualcomm's qpopper is probably the best-of-breed among POP3 servers, and is very widely deployed. Nevertheless, it has some problems which fetchmail exposes. We recommend using IMAP instead if at all possible. If you must talk to qpopper, here are some problems to be aware of:

### Problems with retrieving large messages from qpopper 2.53

Tony Tang <tony@atn.com.hk> reports that there is a bad intercation between fetchmail and qpopper 2.5.3 under Red Hat Linux versions 5.0 to 5.2, kernels 2.0.34 to 2.0.35. When fetching very large messages (over 700K) from 2.5.3, fetchmail will hang with a socket error.

This is probably not a fetchmail bug, but rather a symptom of some problem in the networking stack that qpopper's transmission pattern is tickling, as fetchpop (another Linux POP client) also displays the hang but Netscape running under Win95 does not. The problem can also be banished by upgrading to qpopper 3.0b1.

### Bad interaction with fetchmail 4.4.2 to 4.4.7

Versions of fetchmail from 4.4.2 through 4.4.7 had a bad interaction with Eudora qpopper versions 2.3 and later. See X5 for details. The solution is to upgrade your fetchmail.

## S2. How can I use fetchmail with Microsoft Exchange?

Fetchmail now supports the proprietary NTLM mode used with M$ Exchange servers. To enable this, configure fetchmail with the --enable-NTLM option and recompile it. Note: if you specify a user option value that looks like `user@domain', the part to the left of the @ will be passed as the username and the part to the right as the NTLM domain.

M$ Exchange violates the POP3 RFCs. Its LIST command does not reveal the real sizes of mail in the pop mailbox, but the sizes of the compressed versions in the exchange mail database (thanks to Arjan De Vet and Guido Van Rooij for alerting us to this problem).

Fetchmail works with M$ Exchange, despite this brain damage. Two features are compromised. One is that the --limit option will not work right (it will check against compressed and not actual sizes). The other is that a too-small SIZE argument may be passed to your ESMTP listener, assuming you're using one (this should not be a problem unless the actual size of the message is above the listener's configured length limit).

Somewhat belatedly, I've learned that there's supposed to be a registry bit that can fix this breakage:

    HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MsExchangeIs\Parameters
    System\Pop3 Compatibility

This is a bitmask that controls the variations from the standard protocol. The bits defined are:

0x00000001:
  Report exact message sizes for the LIST command
0x00000002:
  Allow arbitrary linear whitespace between commands and arguments
0x00000004:
  Enable the LAST command
0x00000008:
  Allow an empty PASS command (needed for users with blank passwords, but illegal in the protocol)
0x00000010:
  Relax the length restrictions for arguments to commands (protocol requires 40, but some user names may be longer than that).
0x00000020:
  Allow spaces in the argument to the USER command.

There's another one that may be useful to know about:

    KEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MsExchangeIs\Parameters
    System\Pop3 Performance

0x00000001:
  Render messages to a temporary stream instead of sending directly from the database (should always be on)
0x00000002: Flag unrenderable messages (instead of just failing commands) (should only be on if you are seeing the problems reported in KB Q168109)
0x00000004:
  Return from the QUIT command before all messages have been deleted.

The Microsoft pod-person who revealed this information to me admitted that he couldn't find it anywhere in their public knowledge base.

Another specific problem we have seen with Exchange servers has as its symptom a response to LOGIN that says "NO Ambiguous Alias". Grant Edwards writes: This means that Exchange Server is too f*&#ing stupid to figure out which mailbox belongs to you. Instead of actually keeping track of which inbox belongs to which user, it uses some half-witted, guess-o-matic heuristic to try to guess your mailbox name from your username.

In your case it doesn't work because your username maps to more than one mailbox. For some people it doesn't work because their username maps to zero mailboxes. This is yet another inept, lame, almost criminally negligent design decision from our friends in Redmond.

You've got several options:

- Try giving fetchmail a username of "/NTDomain/NTUsername/MailboxName".
- Get your administrator to configure the server so that usernames and mailbox names are the same.
- Get your administrator to add an alias that maps your username explicitly to your mailbox name.

But, the best option involves a tactical nuclear weapon (an old ASROC will do), pissing off a lot people who live downwind from Redmond, and your choice of any Linux, NetBSD, FreeBSD, or Solaris CD.

I'll provide the CD.

## S3. How can I use fetchmail with CompuServe RPA?

First, make sure your fetchmail has the RPA support compiled in. Stock fetchmail binaries (such as you might get from an RPM) don't. You can check this by looking at the output of `fetchmail -V`; if you see the string "+RPA" after the version ID you're good to go, otherwise you'll have to build your own from sources (see the INSTALL file in the source distribution for directions).

Give your CompuServe pass-phrase in lower case as your password. Add `@compuserve.com' to your user ID so that it looks like `user <UserID>@compuserve.com', where <UserID> can be either your numerical userID or your E-mail nickname. An RPA-enabled fetchmail will automatically check for csi.com in the POP server's greeting line. If that's found, and your user ID ends with `@compuserve.com', it will query the server to see if it is RPA-capable, and if so do an RPA transaction rather than a plain-text password handshake.

Warning: the debug (-v -v) output of fetchmail will show your pass-phrase in Unicode!

These two .fetchmailrc entries show the difference between an RPA and non-RPA configuration:

    # This version will use RPA
    poll csi.com via "pop.site1.csi.com" with proto POP3 and options no dns
        user "CSERVE_USER@compuserve.com" there with password "CSERVE_PASSWORD"
            is LOCAL_USER here options fetchall stripcr

    # This version will not use RPA
    poll non-rpa.csi.com via "pop.site1.csi.com" with proto POP3 and options no dns
        user "CSERVE_USER" there with password "CSERVE_POP3_PASSWORD"
           is LOCAL_USER here options fetchall stripcr

## S4. How can I use fetchmail with Demon Internet's SDPS?

### Single-drop mode

You can get fetchmail to download the email for just one user from Demon Internet's POP3 server by giving it a username consisting of your Demon user name followed by your account name, with an at-sign between them.

For example, to download email for the user <philh@vision25.demon.co.uk>, you could use the following .fetchmailrc file:

    set postmaster "philh"
    poll pop3.demon.co.uk with protocol POP3:
        user "philh@vision25" is philh

### Multi-drop mode

Demon Internet's SDPS service is an implementation of POP3. All messages have a Received: header added when they enter the maildrop, like this:

       Received: from punt-1.mail.demon.net by mailstore for fred@xyz.demon.co.uk
                 id 899963657:10:27896:0; Thu, 09 Jul 98 05:54:17 GMT

To enable multi-drop mode you need to tell fetchmail that 'mailstore' is the name of the host which accepted the mail, and let it know the hostname part(s) of your E-mail address. The following example assumes that your hostname is xyz.demon.co.uk, and that you have also bought "mail forwarding" for the domain my-company.co.uk (in which case your MTA must also be configured to accept mail sent to user@my-company.co.uk)

         poll pop3.demon.co.uk proto pop3 aka mailstore no dns:
           localdomains xyz.demon.co.uk my-company.co.uk
           user xyz is * fetchall

The `fetchall' command ensures that all mail is downloaded. If you want to leave mail on the server use `uidl' and `keep'; Demon does not implement the obsolete `top' command, because SDPS combines messages residing on two separate punt clusters into a single POP3 maildrop. If you do use UIDL, be aware that the "user@host" form for fetching mail from a particular Demon host will confuse fetchmail's UIDL code; use user+host.

Note that Demon may delete mail on the server which is more than 30 days old; see their POP3 page for details.

### The SDPS extension

There's a different way to do multidrop. It's not necessary on Demon Internet, since fetchmail can parse Received addresses, but the person who implemented this didn't know that. It may be useful if Demon Internet ever changes mail transports.

SDPS includes a non-standard extension for retrieving the envelope of a message (*ENV), which fetchmail optionally supports if compiled with the --enable-SDPS option. If you have it, the first line of the fetchmail -V response will include the string "+SDPS".

Once you have SDPS compiled in, fetchmail in POP3 mode will automatically detect when it's talking to a Demon Internet host in multidrop mode, and use the *ENV extension to get an envelope To address.

The autodetection works by looking at the hostname in the POP3 greeting line; if you're accessing Demon Internet through a proxy it may fail. To force SDPS mode, pick "sdps" as your protocol.

## S5. How can I use fetchmail with usa.net's servers?

Enable ``fetchall`'. A user reports that the 2.2 version of USA.NET's POP server reports that you must use the ``fetchall`' option to make sure that all of the mail is retrieved, otherwise some may be left on the server. This is almost certainly a server bug.

The usa.net servers (at least in their 2.2 version, June 1998) don't handle the TOP command properly, either. Regardless of the argument you give it, they retrieve only about 10 lines of the message. Fetchmail normally uses TOP for message retrieval in order to avoid marking messages seen, but ``fetchall`' forces it to use RETR instead.

(Note: Other failure modes have been reported on usa.net's servers. They seem to be chronically flaky. We recommend finding another provider.)

## S6. How can I use fetchmail with HP OpenMail?

No special configuration is required, but OpenMail versions prior to 6.0 have an annoying bug similar to the big one in Microsoft Exchange. The message sizes it gives in the LIST are rounded to the nearest 1024 bytes. It also has a nasty habit of discarding headers it doesn't recognize, such as X- and Resent- headers.

As with M$ Exchange, the only real fix for these problems is to get a POP (or preferably IMAP) server that isn't brain-dead. OpenMail's project manager claims these bugs have been fixed in 6.0.

## S8. How can I use fetchmail with Hotmail?

You can't, yet. But Hugo Rabson has written a script called `hotmole' that can retrieve Hotmail mail via the web using Lynx. The script was available on Hugo Rabson's Linux page, but we're told that project is dead and the web page seems to be gone.

## S9. How can I use fetchmail with MSN?

You can't. MSN uses something that looks like POP3, except the authentication part is nonstandard. And of course they don't document it, so nobody but their Windows clients can speak it.

This is a customer lock-in tactic; we recommend boycotting MSN as the only appropriate response.

As of 5.0.8, we have support for the client side of NTLM authentication. It's possible this may enable fetchmail to talk to MSN; if so, somebody should report it so this FAQ can be corrected.

## S10. How can I use fetchmail with SpryNet?

The SpryNet POP3 servers mark a message queried with TOP as seen. This means that if your connection drops in mid-message, it may end up invisibly stuck on your mail spool. Use the `fetchall` flag to ensure that it's recovered on the next cycle.

## S11. How can I use fetchmail with FTGate?

The FTGate V2 server (and possibly older versions as well) has a weird bug. It answers OK twice to a TOP request! Use the `fetchall` option to force use of RETR and work around this bug.

## S12. How can I use fetchmail with MailMax?

You can't. At least not if you want to be able to see attachments. MailMax has a bug; it reports the message length with attachments but doesn't download them on TOP or RETR.

## S13. How can I use fetchmail with Novell GroupWise?

The Novell GroupWise IMAP server would be better named GroupFoolish; it is (according to the designer of IMAP) unusably broken. Among other things, it doesn't include a required content length in its BODY[TEXT] response.

Fetchmail works around this problem, but we strongly recommend voting with your dollars for a server that isn't brain-dead. If you stick with code as shoddy as GroupWise seems to be, you will probably pay for it with other problems.

## S14. How can I use fetchmail with InterChange?

You can't. At least not if you want to be able to see attachments. InterChange has a bug similar to the MailMax server; it reports the message length with attachments but doesn't download them on TOP or RETR.

## K1. How can I use fetchmail with SOCKS?

Daniel Sobral <dcs@gns.com.br gave us the following recipe:

1. Install socks5. You don't need to have a socks server, you just want the "runsocks" program.
2. Set the environment variable SOCKS_SERVER to the server you'll be using. Alternatively, you may set SOCKS4_SERVER and/or SOCKS5_SERVER. E.g.:

       	export SOCKS5_SERVER=socks.my.domain.com

3. Set SOCKS5_USER and SOCKS5_PASSWD if needed.
4. Run fetchmail through runsocks. Just like this:

       	runsocks fetchmail [parameters to fetchmail]

It wasn't that hard, was it? :-)

Giuseppe Guerini added a --with-socks option that supports linking with socks library. If you specify the value of this option as ``yes'', the configure script will try to find the Rconnect library and set the makefile up to link it. You can also specify a directory containing the Rconnect library.

## S7. How can I use fetchmail with geocities POP3 servers?

Nathan Cutler reports that the the mail.geocities.com POP3 servers fail to include the first Received line of the message in the send to fetchmail. This can solve problems if your MUA interprets Received continuations as body lines and doesn't parse any of the following headers.

Workaround is to use "mda" keyword or "-mda" switch:

    mda "sed -e '1s/^\t/Received: /' | formail | /usr/bin/procmail -d <user>"

Replace \t with exactly one tabulation character. You should also consider using "fetchall" option because Geocities' servers sometimes think that the first 45 messages have already been read.

Fix: Get an email provider that doesn't suck. The pop-up ads on Geocities are lame, you should boycott them anyway.

## K2. How can I use fetchmail with IPv6 and IPsec?

To use fetchmail with IPv6, you need a system that supports IPv6, the "Basic Socket Interface Extensions for IPv6" (RFC 2133). This currently means that you need to have a BSD/OS or NetBSD system with the NRL IPv6+IPsec software distribution or a Linux system with the latest experimental kernel and net-tools. It should not be hard to build fetchmail on other IPv6 implementations if you can port the inet6-apps kit.

To use fetchmail with networking security (read: IPsec), you need a system that supports IPsec, the API described in the "Network Security API for Sockets" (draft-metz-net-security-api-01.txt), and the inet6-apps kit. This currently means that you need to have a BSD/OS or NetBSD system with the NRL IPv6+IPsec software distribution. A Linux IPsec implementation supporting this API will probably appear in the coming months.

The NRL IPv6+IPsec software distribution can be obtained from: http://web.mit.edu/network/isakmp

The inet6-apps kit can be obtained from ftp://ftp.ipv6.inner.net/pub/ipv6 (via IPv6) or ftp://ftp.inner.net/pub/ipv6 (via IPv4).

More information on using IPv6 with Linux can be obtained from:

- http://www.bieringer.de/linux/IPv6/IPv6-HOWTO/IPv6-HOWTO.html
- http://www.ipv6.inner.net/ipv6 (via IPv6)
- http://www.inner.net/ipv6 (via IPv4)

## K3. How can I get fetchmail to work with ssh?

We have three recipes for this. The first is easy to set up, but only supports one user at a time.

### Single-User POP3

First, a lightly edited version of a recipe from Masafumi NAKANE:

1. You must have ssh (the ssh client) on the local host and sshd (ssh server) on the remote mail server. And you have to configure ssh so you can login to the sshd server host without a password. (Refer to ssh man page for several authentication methods.)

2. Add something like following to your .fetchmailrc file:

    poll mailhost port 1234 via localhost with proto pop3:
            preconnect "ssh -f -L 1234:mailhost:110 mailhost
            </dev/null >/dev/null; sleep 5";

The sleep is needed on slower machines to prevent fetchmail from trying to open the socket before ssh actually makes it ready. Faster machines may not need it.

(Note that 1234 can be an arbitrary port number. Privileged ports can be specified only by root.) The effect of this ssh command is to forward connections made to localhost port 1234 (in above example) to mailhost's 110.

This configuration will enable secure mail transfer. All the conversation between fetchmail and remote pop server will be encrypted.

If sshd is not running on the remote mail server, you can specify intermediate host running it. If you do this, however, communication between the machine running sshd and the POP server will not be encrypted. And the preconnect line would be like this:

    preconnect "ssh -f -L 1234:mailhost:110 sshdhost sleep 20 </dev/null >/dev/null"

You can work this trick with IMAP too, but the port number 110 in the above would need to become 143. In either case you'll have to specify a password but the password will not be sent in clear.

There is an explanation of a similar recipe at Secure POP via SSH mini-HOWTO.

### Multi-User POP3

Second, a recipe from Charlie Brady <cbrady@ind.tansu.com.au>:

Charlie says: "The recipe [from Masafume NAKANE] certainly works, but the solution I post here is better in a few respects":

- this method will not fail if two or more users attempt to use fetchmail simultaneously.
- you are able to use the full facilities of tcpd to control access
- this method does not depend on the preconnect feature of fetchmail, so can be used for tunneling of other services as well.

Here are the steps:

1. Make sure that the "socket" program is installed on the server machine. Presently it lives at ftp://sunsite.unc.edu/pub/linux/system/network/misc/socket-1.1.tar.gz, but watch out for a change in version number.

2. Set up an unprivileged account on your system with a .ssh directory containing an SSH identity file "identity" with no pass phrase, "identity.pub" and "known_hosts" containing the host key of your mailhost. Let's call this account "noddy".
3. On mailhost, set up no-password access for noddy@yourhost. Add to your SSH authorized_keys file:

       command="socket localhost 110",no-port-forwarding 1024 ......

   where "`1024 ......`" is the content of noddy's identity.pub file.
4. Create a script /usr/local/bin/ssh.fm and make it executable:

       #! /bin/sh
       exec ssh -q -C -l your.login.id -e none mailhost socket localhost 110

5. Add an entry in inetd.conf for whatever port you choose to use - say:

       1234 stream tcp nowait noddy /usr/sbin/tcpd /usr/local/bin/ssh.fm

6. Send a HUP signal to your inetd.

Now just use localhost:1234 to access your POP server.

### Multi-User IMAP

This is the preferred method. It comes to us from Joerg Dorchain. The basic idea is to set up a bidirectional encrypted socket connection:

    fetchmail <--> ssh <---> sshd <--> imapd
     \---local side--/       \-remote side-/

Use ssh-keygen(1) to set up a special ssh identity with no password and RSA-only authentication, which executes /usr/sbin/imapd when authenticated. For security reasons all other commands should be disabled. (There is some security exposure in using an identity without a passphrase; it means anyone who can get access to your account could use it to read your mail).

Running ssh-keygen will generate two files. Have it create the private key to ~/.ssh/identity-imap. Once you have generated the corresponding public key, prepend this to the line of key data in it:

    command="/usr/sbin/imapd",no-port-forwarding,no-agent-forwarding

This identity data has to be appended to ~/.ssh/authorized_keys on the remote machine, as usual for RSA authentication. Whenever your ssh uses this identity, the remote side will run imapd. The imapd will see that it is not running as root and go into preauthenticated mode.

On the client side, use the `plugin` keyword to make fetchmail talk to the stdin of the remote ssh. Here's an examople:

    poll mail.dorchain.net options proto imap plugin fetchmail-imap-wrapper

The wrapper script should look like this:

    #!/bin/sh
    exec ssh -i $HOME/.ssh/identity-imap $1 /usr/sbin/imapd

## K4. What do I have to do to use the IMAP-GSS protocol?

Fetchmail can use RFC1731 GSSAPI authorization to safely identify you to your IMAP server, as long as you can share Kerberos V credentials with your mail host and you have a GSSAPI-capable IMAP server. UW-IMAP (available via FTP at ftp.cac.washington.edu) is the only one I'm aware of and the one I recommend anyway for other reasons. You'll need version 4.1-FINAL or greater though, and it has to have GSS support compiled in.

Neither UW-IMAP nor fetchmail compile in support for GSS by default, since it requires libraries from the Kerberos V distribution (available via FTP at athena-dist.mit.edu but mind the export restrictions). If you have these, compiling in GSS support is simple: add a

    --with-gssapi=[/path/to/krb5/root]

option to configure. For instance, I have all of my Kerberos V libraries installed under /usr/krb5 so I run

    configure --with-gssapi=/usr/krb5

Setting up Kerberos V authentication is beyond the scope of this FAQ (you may find Jim Rome's paper How to Kerberize your site helpful), but you'll at least need to add a credential for imap/[mailhost] to the keytab of the mail server (IMAP doesn't just use the host key). Then you'll need to have your credentials ready on your machine (cf. kinit).

After that things are very simple. Set your protocol to imap-gss in your .fetchmailrc, and omit the password, since imap-gss doesn't need one. You can specify a username if you want, but this is only useful if your mailbox belongs to a username different from your Kerberos principal.

Now you don't have to worry about your password appearing in cleartext in your .fetchmailrc, or across the network.

## K5. How can I use fetchmail with SSL?

You'll need to have the OpenSSL libraries installed. Configure with --with-ssl. If you have the OpenSSL libraries installed in the default location (/usr/local/ssl) this will suffice. If you have them installed in a non-default location, you'll need to specify it as an argument to --with-ssl after an equal sign.

Fetchmail binaries built this way support `ssl`, `sslkey`, and `sslcert` options that control SSL encryption. You will need to have an SSL-enabled mailserver to use these options. See the manual page for detals.

## R1. Fetchmail isn't working, and -v shows `SMTP connect failed' messages.

Fetchmail itself is probably working, but your SMTP port 25 listener is down or inaccessible.

The first thing to check is if you can telnet to port 25 on your smtp host (which is normally `localhost' unless you've specified an smtp option in your .fetchmailrc or on the command line) and get a greeting line from the listener. If the SMTP host is inaccessible or the listener is down, fix that first.

If the listener seems to be up when you test with telnet, the most benign and typical problem is that the listener had a momentary seizure due to resource exhaustion while fetchmail was polling it -- process table full or some other problem that stopped the listener process from forking. If your SMTP host is not `localhost' or something else in /etc/hosts, the fetchmail glitch could also have been caused by transient nameserver failure.

Try running fetchmail -v again; if it succeeds, you had one of these kinds of transient glitch. You can ignore these hiccups, because a future fetchmail run will get the mail through.

If the listener tests up, but you have chronic failures trying to connect to it anyway, your problem is more serious. One way to work around chronic SMTP connect problems is to use --mda. But this only attacks the symptom; you may have a DNS or TCP routing problem. You should really try to figure out what's going on underneath before it bites you some other way.

We have one report (from toby@eskimo.com) that you can sometimes solve such problems by doing an `smtp` declaration with an IP address that your routing table maps to something other than the loopback device (he used ppp0).

We also have a report that this error can be caused by having an /etc/hosts file that associates your client host name with more than one IP address.

It's also possible that your DNS configuration isn't looking at `/etc/hosts` at all. If you're using libc5, look at `/etc/resolv.conf`; it should say something like

            order hosts,bind

so your `/etc/hosts` file is checked first. If you're running GNU libc6, check your `/etc/nsswitch.conf` file. Make sure it says something like

            hosts:  files dns

again, in order to make sure `/etc/hosts` is seen first.

If you have a hostname set for your machine, and this hostname does not appear in /etc/hosts, you will be able to telnet to port 25 and even send a mail with rcpt to: user@host-not-in-/etc/hosts, but fetchmail can't seem to get in touch with sendmail, no matter what you set smtpaddress to.

We had another report from a Linux user of fetchmail 2.1 who solved his SMTP connection problem by removing the reference to -lresolv from his link line and relinking. Apparently in some older Linux distributions the libc bind library version works better.

As of 2.2, the configure script has been hacked so the bind library is linked only if it is actually needed. So under Linux it won't be, and this particular cause should go away.

## R2. When I try to configure an MDA, fetchmail doesn't work.

(I hear this one from people who have run into the blank-line problem in X1.)

Try sending yourself test mail and retrieving it using the command-line options ``-k -m cat`'. This will dump exactly what fetchmail retrieves to standard output (plus the Received line fetchmail itself adds to the headers).

If the dump doesn't match what shows up in your mailbox when you configure an MDA, your MDA is mangling the message. If it doesn't match what you sent, then fetchmail or something on the server is broken.

## R3. Fetchmail dumps core when given an invalid rc file.

This is usually reported from AIX or Ultrix, but has even been known to happen on Linuxes without a recent version of `flex` installed. The problem appears to be a result of building with an archaic version of lex.

Workaround: fix the syntax of your .fetchmailrc file.

Fix: build and install the latest version of flex from the Free Software Foundation. An FSF mirror site will help you get it faster.

## R4. Fetchmail dumps core in -V mode, but operates normally otherwise.

We've had this reported to us under Linux using libc-5.4.17 and gcc-2.7.2. It does not occur with libc-5.3.12 or earlier versions.

Workaround: link with GNU malloc rather than the stock C library malloc.

We're told there is some problem with the malloc() code in that version which makes it fragile in the presence of multiple free() calls on the same pointer (the malloc arena gets corrupted). Unfortunately it appears from doing gdb traces that whatever free() calls producing the problem are being made by the C library itself, not the fetchmail code (they're all from within fclose, and not an fclose called directly by fetchmail, either).

## R5. Running fetchmail in daemon mode doesn't work.

We have one report from a SunOS 4.1.4 user that trying to run fetchmail in detached daemon mode doesn't work, but that using the same options with -N (nodetach) is OK.

If this happens, you have a specific portability problem with the code in daemon.c that detaches and backgrounds the daemon fetchmail. Tell me about it so I can try to fix it. As a workaround, you can start fetchmail with -N and an ampersand to background it. A Sun user recommends this:

    (fetchmail --nodetach <other params> &)

The extra pair of parens is significant --- it makes sure that the process detaches from the initial shell (one more shell is started and dies immediately, detaching fetchmail and making it child of PID 1). This is important when you start fetchmail interactively and than quit interactive shell. The line above makes sure fetchmail lives after that!

This should not happen under Linux or any truly POSIX-conformant Unix.

## R6. Fetchmail hangs when used with pppd.

Your problem may be with pppd's `demand' option. We have a report that fetchmail doesn't play well with it, but works with pppd if `demand' is turned off. We have no idea why this is.

## R7. Fetchmail randomly dies with socket errors.

Check the MTU value in your PPP interface reported by `/sbin/ifconfig`. If it's over 600, change it in your PPP options file. (`/etc/ppp/options` on my box). Here are option values that work:

      mtu 552
      mru 552

R8. Fetchmail running as root stopped working after an OS upgrade In RH 6.0, the HOME value in the boot-time root environment changed from /root to / as the result of a change in init. Move your .fetchmailrc or use a -f option to explicitly point at the file. (Oddly, a similar problem has been reported from Debian systems.)

## R9. Fetchmail is timing out after fetching certain messages but before deleting them

There's a TCP/IP stalling problem under Redhat 6.0 (and possibly other recent Linuxes) that can cause this symptom. Brian Boutel writes:

> TCP timestamps are turned on on my Linux boxes (I assume it's now the default). This uses 12 extra bytes per segment. When the tcp connection starts, the other end agrees a MSS of 1460, and then fragments 1460 byte chunks into 1448 and 12, because is is not allowing for the timestamp.

> Then, for reasons I can't explain, it waits a long time (typically 2 minutes) after the ack is sent before sending the next (fragmented) packet. Turning off tcp timestamps avoids the fragmentation and restores normal behaviour. To do this, [execute]

> echo 0 > /proc/sys/net/ipv4/tcp_timestamps

> I'm still unclear about the details of why this is happening. At least [now] I am now getting good performance and no queue blocking.

## R10. Fetchmail is timing out during message fetches

This is probably a general networking issue. Sending a "RETR" command will cause the server to start sending large amounts of data, which means large packets. If your networking layer has a packet-fragmentation problem, that's where you'll see it.

## D1. I think I've set up fetchmail correctly, but I'm not getting any mail.

Maybe you have a .forward or alias set up that you've forgotten about. You should probably remove it.

Or maybe you're trying to run fetchmail in multidrop mode as root without a .fetchmailrc file. This doesn't do what you think it should; see question C1.

Or you may not be connecting to the SMTP listener. Run fetchmail -v and see R1.

## D2. All my mail seems to disappear after a dropped connection.

One POP3 daemon used in the Berkeley Unix world that reports itself as POP3 version 1.004 actually throws the queue away. 1.005 fixed that. If you're running this one, upgrade immediately. (It also truncates long lines at column 1024)

Many POP servers, if an interruption occurs, will restore the whole mail queue after about 10 minutes. Others will restore it right away. If you have an interruption and don't see it right away, cross your fingers and wait ten minutes before retrying.

Some servers (such as Microsoft's NTMail) are mis-designed to restore the entire queue, including messages you have deleted. If you have one of these and it flakes out on you a lot, try setting a small `--fetchlimit` value. This will result in more IP connects to the server, but will mean it actually executes changes to the queue more often.

Qualcomm's qpopper, used at many BSD Unix sites, is better behaved. If its connection is dropped, it will first execute all DELE commands as though you had issued a QUIT (this is a technical violation of the POP3 RFCs, but a good idea in a world of flaky phone lines). Then it will re-queue any message that was being downloaded at hangup time. Still, qpopper may require a noticeable amount of time to do deletions and clean up its queue. (Fetchmail waits a bit before retrying in order to avoid a `lock busy' error.)

## D3. Mail that was being fetched when I interrupted my fetchmail seems to have been vanished.

Fetchmail only sends a delete mail request to the server when either (a) it gets a positive delivery acknowledgment from the SMTP listener, or (b) it gets an error 571 (the spam-filter error) from the listener. No interrupt can cause it to lose mail.

However, IMAP2bis has a design problem in that its normal fetch command marks a message `seen' as soon as the fetch command to get it is sent down. If for some reason the message isn't actually delivered (you take a line hit during the download, or your port 25 listener can't find enough free disk space, or you interrupt the delivery in mid-message) that `seen' message can lurk invisibly in your server mailbox forever.

Workaround: add the ``fetchall`' keyword to your fetch options.

Solution: switch to an IMAP4 server.

## M1. I've declared local names, but all my multidrop mail is going to root anyway.

Somehow your fetchmail is never recognizing the hostname part of recipient names it parses out of To/Cc/envelope-header lines as matching the name of the mailserver machine. To check this, run fetchmail in foreground with -v -v on. You will probably see a lot of messages with the format ``line rejected, %s is not an alias of the mailserver'' or ``no address matches; forwarding to %s.''

These errors usually indicate some kind of DNS configuration problem either on the server or your client machine.

The easiest workaround is to add a ``via`' option (if necessary) and add enough aka declarations to cover all of your mailserver's aliases, then say ``no dns`'. This will take DNS out of the picture (though it means mail may be uncollected if it's sent to an alias of the mailserver that you don't have listed).

It would be better to fix your DNS, however. DNS problems can hurt you in lots of ways, for example by making your machines intermittently or permanently unreachable to the rest of the net.

Occasionally these errors indicate the sort of header-parsing problem described in M7.

## M2. I can't seem to get fetchmail to route to a local domain properly.

A lot of people want to use fetchmail as a poor man's internetwork mail gateway, picking up mail accumulated for a whole domain in a single server mailbox and then routing based on what's in the To/Cc/Bcc lines.

In general, this is not really a good idea. It would be smarter to just let the mail sit in the mailserver's queue and use fetchmail's ETRN mode to trigger SMTP sends periodically (of course, this means you have to poll more frequently than the mailserver's expiration period). If you can't arrange this, try setting up a UUCP feed.

If neither of these alternatives is available, multidrop mode may do (though you are going to get hurt by some mailing list software; see the caveats under THE USE AND ABUSE OF MULTIDROP MAILBOXES on the man page). If you want to try it, the way to do it is with the ``localdomains`' option.

In general, if you use localdomains you need to make sure of two other things:

1. You've actually set up your .fetchmailrc entry to invoke multidrop mode.

Many people set a ``localdomains`' list and then forget that fetchmail wants to see more than one name (or the wildcard `*') in a ``here`' list before it will do multidrop routing.

2. You may have to set `no envelope'.

Normally, multidrop mode tries to deduce an envelope address from a message before parsing the To/Cc/Bcc lines (this enables it to avoid losing to mailing list software that doesn't put a recipient address in the To lines).

Some ways of accumulating a whole domain's messages in a single server mailbox mean it all ends up with a single envelope address that is useless for rerouting purposes. You may have to set ``no envelope`' to prevent fetchmail from being bamboozled by this.

Check also answer T1 on a reliable way to do multidrop delivery if your ISP (or your mail redirection provider) is using qmail.

## M3. I tried to run a mailing list using multidrop, and I have a mail loop!

This isn't fetchmail's fault. Check your mailing list. If the list expansion includes yourself or anybody else at your mailserver (that is, not on the client side) you've created a mail loop. Just chop the host part off any local addresses in the list.

If you use sendmail, you can check the list expansion with `sendmail -bv`.

## M4. My multidrop fetchmail seems to be having DNS problems.

We have one report from a Linux user (not the same one as in R1!) who solved this problem by removing the reference to -lresolv from his link line and relinking. Apparently in some older Linux distributions the libc5 bind library version works better.

As of 2.2, the configure script has been hacked so the bind library is linked only if it is actually needed. So under Linux it won't be, and this problem should go away.

## M5. I'm seeing long DNS delays before each message is processed.

Use the ``aka`' option to pre-declare as many of your mailserver's DNS names as you can. When an address's host part matches an aka name, no DNS lookup needs to be done to check it.

If you're sure you've pre-declared all of your mailserver's DNS names, you can use the ``no dns`' option to prevent other hostname parts from being looked up at all.

Sometimes delays are unavoidable. Some SMTP listeners try to call DNS on the From-address hostname as a way of checking that the address is valid.

## M6. How do I get multidrop mode to work with majordomo?

In order for sendmail to execute the command strings in the majordomo alias file, it is necessary for sendmail to think that the mail it receives via SMTP really is destined for a local user name. A normal virtual-domain setup results in delivery to the default mailbox, rather than expansion through majordomo.

Michael <michael@bizsystems.com> gave us a recipe for dealing with this case that pairs a run control file like this:

    poll your.pop3.server proto pop3:
        no envelope no dns
        localdomains virtual.localdomain1.com virtual.localdomain2.com ...
        user yourISPusername is root * here,
        password yourISPpassword fetchall

with a hack on your local sendmail.cf like this:

    #############################################
    #  virtual info, local hack for ruleset 98  #
    #############################################

    # domains to treat as direct mapped local domain

    CVvirtual.localdomain1.com virtual.localdomain2.com ...
    ---------------------------
    in ruleset 98 add
    -------------------------
    # handle virtual users

    R$+ <@ $=V . >          $: $1 < @ $j . >
    R< @ > $+ < @ $=V . >   $: $1 < @ $j . >
    R< @ > $+               $: $1
    R< error : $- $+ > $*   $#error $@ $1 $: $2
    R< $+ > $+ < @ $+ >     $: $>97 $1

This ruleset just strips virtual domain names off the addresses of incoming mail. Your sendmail must be 8.8 or newer for this to work. Michael says:

> I use this scheme with 2 virtual domains and the default ISP user+domain and service about 30 mail accounts + majordomo on my inside pop3 server with fetchmail and sendmail 8.83

## M7. Multidrop mode isn't parsing envelope addresses from my Received headers as it should.

It may happen that you're getting what appear to be well-formed sendmail Received headers, but fetchmail can't seem to extract an envelope address from them. There can be a couple of reasons for this.

### Spurious Received lines need to be skipped:

First, fetchmail might be looking at the wrong Received header. Normally it looks only on the first one it sees, on the theory that that one was last added and is going to be the one containing your mailserver's theory of who the message was addressed to.

Some (unusual) mailserver configurations will generate extra Received lines which you need to skip. To arrange this, use the optional skip prefix argument of the `envelope' option; you may need to say something like ``envelope 1 Received`' or ``envelope 2 Received`'.

### The `by' clause doesn't contain a mailserver alias:

When fetchmail parses a Received line that looks like

    Received: from send103.yahoomail.com (send103.yahoomail.com [205.180.60.92])
        by iserv.ttns.net (8.8.5/8.8.5) with SMTP id RAA10088
        for <ksturgeon@fbceg.org>; Wed, 9 Sep 1998 17:01:59 -0700

it checks to see if `iserv.ttns.net' is a DNS alias of your mailserver before accepting `ksturgeon@fbceg.org' as an envelope address. This check might fail if your DNS were misconfigured, or if you were using `no dns' and had failed to declare iserv.ttns.net as an alias of your server.

## M8. Users are getting multiple copies of messages.

It's a consequence of multidrop. What's happening is that you have N users subscribed to the same list. The list software sends N copies, not knowing they will end up in the same multidrop box. Since they are both locally addressed to all N users, fetchmail delivers N copies to each user.

Fetchmail tries to eliminate adjacent duplicate messages in a multidrop mailbox. However, this logic depends on the message-ID being identical in both copies. It also depends on the two copies being adjacent in the server mailbox. The former is usually the case, but the latter condition sometimes fails in a timing-dependent way if the server was processing multiple incoming mail streams. I could eliminate this problem by keeping a list of all message-IDs received during a poll so far and dropping any message that matches a seen mail ID. The touble is that this is an O(N**2) operation that might significantly slow down the retriweval of large mail batches.

## X1. Spurious blank lines are appearing in the headers of fetched mail.

What's probably happening is that the POP/IMAP daemon on your mailserver is inserting a non-RFC822 header (like X-POP3-Rcpt:) and something in your delivery path (most likely an old version of the deliver program, which sendmail often calls to do local delivery) is failing to recognize it as a header.

This is not fetchmail's problem. The first thing to try is installing a current version of deliver. If this doesn't work, try to figure out which other program in your mail path is inserting the blank line and replace that. If you can't do either of these things, pick a different MDA (such as procmail) and declare it with the ``mda`' option.

## X2. My mail client can't see a Subject line.

First, see X1. This is quite probably the same problem (X-POP3-Rcpt header or something similar being inserted by the server and choked on by an old version of deliver).

The O'Reilly sendmail book does warn that IDA sendmail doesn't process X- headers correctly. If this is your problem, all I can suggest is replacing IDA sendmail, because it's broken and not RFC822 conformant.

## X3. Messages containing "From" at start of line are being split.

If you know the messages aren't split in your server mailbox, then this is a problem with your POP/IMAP server, your client-side SMTP listener or your local delivery agent. Fetchmail cannot split messages.

Some POP server daemons ignore Content-Length headers and split messages on From lines. We have one report that the 2.1 version of the BSD popper program (as distributed on Solaris 2.5 and elsewhere) is broken this way.

You can test this. Declare an mda of `cat' and send yourself one piece of mail containing "From" at start of a line. If you see a split message, your POP/IMAP server is at fault. Upgrade to a more recent version.

Sendmail and other SMTP listeners don't split RFC822 messages either. What's probably happening is either sendmail's local delivery agent or your mail reader are not quite RFC822-conformant and are breaking messages on what it thinks are Unix-style From headers. You can figure out which by looking at your client-side mailbox with vi or more. If the message is already split in your mailbox, your local delivery agent is the problem. If it's not, your mailreader is the problem.

If you can't replace the offending program, take a look at your sendmail.cf file. There will likely be a line something like

    Mlocal, P=/usr/bin/procmail, F=lsDFMShP, S=10, R=20/40, A=procmail -Y -d $u

describing your local delivery agent. Try inserting the `E' option in the flags part (the F= string). This will make sendmail turn each dangerous start-of-line From into a >From, preventing programs further downstream from acting up.

## X4. My mail is being mangled in a new and different way

The first thing you need to do is pin down what program is doing the mangling. We don't like getting bug reports about fetchmail that are actually due to some other program's malfeasance, so please go through this diagnostic sequence before sending us a complaint.

There are five possible culprits to consider, listed here in the order they pass your mail:

1. Programs upstream of your server mailbox.
2. The POP or IMAP server on your mailserver host.
3. The fetchmail program itself.
4. Your local sendmail.
5. Your LDA (local delivery agent), as called by sendmail or specified by `mda`.

Often it happens that fetchmail itself is OK, but using it exposes pre-existing bugs in your downstream software, or your downstream software has a bad interaction with POP/IMAP. You need to pin down exactly where the message is being garbled in order to deduce what is actually going on.

The first thing to do is send yourself a test message, and retrieve it with a .fetchmailrc entry containing the following (or by running with the equivalent command-line options):

        mda "cat >MBOX" keep fetchall

This will capture what fetchmail gets from the server, except for (a) the extra Received header line fetchmail prepends, (b) header address changes due to `rewrite`, and (c) any end-of-line changes due to the `forcecr` and `stripcr` options. MBOX will in fact contain what programs downstream of fetchmail see.

The most common causes of mangling are bugs and misconfigurations in those downstream programs. If MBOX looks unmangled, you will know that is what is going on and that it is not fetchmail's problem. Take a look at the other FAQ items in this section for possible clues about how to fix your problem.

If MBOX looks mangled, the next thing to do is compare it with your actual server mailbox (if possible). That's why you specified `keep`, so the server copy would not be deleted. If your server mailbox looks mangled, programs upstream of your server mailbox are at fault. Unfortunately there is probably little you can do about this aside from complaining to your site postmaster, and nothing at all fetchmail can do about it!

More likely you'll find that the server copy looks OK. In that case either the POP/IMAP server or fetchmail is doing the mangling. To determine which, you'll need to telnet to the server port and simulate a fetchmail session yourself. This is not actually hard (both POP3 and IMAP are simple, text-only, line-oriented protocols) but requires some attention to detail. You should be able to use a fetchmail -v log as a model for a session, but remember that the "*" in your LOGIN or PASS command dump has to be replaced with your actual password.

The objective of manually simulating fetchmail is so you can see exactly what fetchmail sees. If you see a mangled message, then your server is at fault, and you probably need to complain to your mailserver administrators. However, we like to know what the broken servers are so we can warn people away from them. So please send us a transcript of the session including the mangling and the server's initial greeting line. Please tell us anything else you think might be useful about the server, like the server host's operating system.

If your manual fetchmail simulation shows an unmangled message, congratulations. You've found an actual fetchmail bug, which is a pretty rare thing these days. Complain to us and we'll fix it. Please include the session transcript of your manual fetchmail simulation along with the other things described in the FAQ entry on reporting bugs.

## X5. Using POP3, retrievals seems to be fetching too much!

This may happen in versions of fetchmail after 4.4.1 and before 4.4.8. Versions after 4.4.1 use POP3's TOP command rather than RETR, in order to avoid marking the message seen (leaving it unseen is helpful for later recovery if you lose your connection in the middle of a retrieval).

Versions of fetchmail from 4.4.2 through 4.4.7 had a bad interaction with Eudora qpopper versions 2.3 and later. The TOP bounds check was fooled by an overflow condition in the TOP argument. Decrementing the TOP argument in 4.4.7 fixed this.

Fix: Upgrade to a later version of fetchmail.

Workaround: set the `fetchall` option. Under POP3 in these fetchmail version only, this had the side effect of forcing RETR use.

## O1. The --logfile option doesn't work if the logfile doesn't exist.

This is a feature, not a bug. It's in line with normal practice for system daemons and allows you to suppress logging by removing the log, without hacking potentially fragile startup scripts. To get around it, just touch(1) the logfile before you run fetchmail (this will have no effect on the contents of the logfile if it already exists).

## O2. Every time I get a POP or IMAP message the header is dumped to all my terminal sessions.

Fetchmail uses the local sendmail to perform final delivery, which Netscape and other clients doesn't do; the announcement of new messages is done by a daemon that sendmail pokes. There should be a ``biff'' command to control this. Type

    biff n

to turn it off. If this doesn't work, try the command

    chmod -x `tty`

which is essentially what `biff -n` will do. If this doesn't work, comment out any reference to ``comsat'' in your /etc/inetd.conf file and restart inetd.

In Slackware Linux distributions, the last line in /etc/profile is

    biff y

Change this to

    biff n

to solve the problem system-wide.

## O3. Does fetchmail reread its rc file every poll cycle?

No, but versions 5.2.2 and later will notice when you modify your rc file and restart, reading it.

## O4. Why do deleted messages show up again when I take a line hit while downloading?

Because you're using a POP3 other than Qualcomm qpopper, or an IMAP with a long expunge interval.

According to the POP3 RFCs, deletes aren't actually performed until you issue the end-of-session QUIT command. Fetchmail cannot fix this, because doing it right takes cooperation from the server. There are two possible remedies:

One is to switch to qpopper (the free POP3 server from Qualcomm, the Eudora people). The qpopper software violates the POP3 RFCs by doing an expunge (removing deleted messages) on a line hangup, as well as on processing a QUIT command.

The other (which we recommend) is to switch to IMAP. IMAP has an explicit expunge command and fetchmail normally uses it to delete messages immediately after they are downloaded.

If you get very unlucky, you might take a line hit in the window between the delete and the expunge. If you've set a longer expunge interval, the window gets wider. This problem should correct itself the next time you complete a successful query.

## O5. Why is fetched mail being logged with my name, not the real From address?

Because logging is done based on the address indicated by the sending SMTP's MAIL FROM, and some listeners are picky about that address.

Some SMTP listeners get upset if you try to hand them a MAIL FROM address naming a different host than the originating site for your connection. This is a feature, not a bug -- it's supposed to help prevent people from forging mail with a bogus origin site. (RFC 1123 says you shouldn't do this exclusion...)

Since the originating site of a fetchmail delivery connection is localhost, this effectively means these picky listeners will barf on any MAIL FROM address fetchmail hands them with an @ in it!

Versions 2.1 and up try the header From address first and fall back to the calling-user ID. So if your SMTP listener isn't picky, the log will look right.

## O6. I'm seeing long sendmail delays or hangs near the start of each poll cycle.

Sendmail does a hostname lookup when it first starts up, and also each time it gets a HELO in listener mode.

Your resolver configuration may be causing one of these lookups to fail and time out. Check `/etc/resolv.conf` and `/etc/hosts` file. Make sure your hostname and fully-qualified domain name are both in `/etc/hosts`, and that hosts is looked at before DNS is queried. You probably also want your remote mail server(s) to be in the hosts file.

You can suppress the startup-time lookup if need to by reconfiguring with `FEATURE(nodns)`.

Configuring your bind library to cache DNS lookups locally may help, and is a good idea for speeding up other services as well. Switching to a faster MTA like qmail or exim might help.

## O7. Why doesn't fetchmail deliver mail in date-sorted order?

Because that's not the order the server hands it to fetchmail in.

Fetchmail getting mail from a POP server delivers mail in the order that your server delivers mail. Fetchmail can't do anything about this; it's a limitation of the underlying POP protocol.

In theory it might be possible for fetchmail in IMAP mode to sort messages by date, but this would be in violation of two basics of fetchmail's design philosophy: (a) to be as simple and transparent a pipe as possible, and (b) to hide, rather than emphasize, the differences between the remote-fetch protocols it uses.

Re-ordering messages is a user-agent function, anyway.

## O8. I'm using pppd. Why isn't my monitor option working?

There is a combination of circumstances that can confuse fetchmail. If you have set up demand dialing with pppd, and pppd has an idle timeout, and you have lcp-echo-interval set, then the lcp-echo-interval time must be longer than the pppd idle timeout. Otherwise it is going keep increasing the packet counters that fetchmail relies upon, triggering fetchmail into polling after its own delay interval and thus preventing the pppd link from ever reaching its inactivity timeout.

## O9. Why does fetchmail keep retrieving the same messages over and over?

First, check to see that you haven't enabled the keep and fetchall option. If you have, turn keep off.

This can also happen when some other mail client is logged in to your mail server, if it uses a simple exclusive-locking scheme (and many, especially most POP3 servers, do exactly that). Your fetchmail is able to retrieve the messages, but because the mailbox is write-locked by the other instance yours can neither mark messages seen or delete them. The solution is to either (a) wait for the other client to finish, or (b) terminate it.

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