Virtual email domain: Some problems

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## 7. Some problems

## 7.1 All outgoing email from virtual domain are masquerared

This is caused by a bad DNS configuration. Mostly any mail leaving the server and originating from a virtual domain is rewritten so it looks like it comes from the main domain of the server.

This problem originates from a new sendmail behavior. At startup sendmail scans all network interfaces (and IP aliases) and retrieves the name associated with their IP number. It assumes from now on that all those names are equivalent to the main domain of the server. Any email originating from one of those name will be masqueraded as coming from the main domain.

The DNS problem is simply that you have set the reverse mapping for an IP number so it point to a domain name instead of a host of this domain. Linuxconf will not let you do this mistake as it never does a reverse mapping pointing to a domain name. Doing a DNS by hand does not prevent that though.

So make sure that all IP numbers associated to IP aliases point to a host of a domain, not a domain itself. Restart your DNS and your sendmail and all will be fine.

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