I have a large mail server with about 18000 domains. There are also some servers that NFS mount /var/vpopmail/domains /var/qmail/control /var/qmail/users from the backend mail server.
For some months, its been working fine - all incoming SMTP/POP requests go to the front end boxes, and it all works fine. However of late two of the 18000 domains have been acting up. For some reason, the front end servers are relaying - not accepting - mail for two domains. The only strange thing about their setup is that there is an anti-virus system which has a lower number MX record, so gets the mail and forwards it these mail servers. For 200 other cases, after its virus scanned, the mail servers accept the mail. In these two, it relays it back to the AV server, causing a loop. Both domain names are mentioned in: /var/qmail/control/rcpthosts /var/qmail/users/assign /var/qmail/control/virtualdomains But its still not storing the mail locally. Has anyone else ever seen this ? I don't even know where to start looking for a cause. Is there an easy way of running strace over some qmail daemon to see how it works out what to do with mail on a vpopmail system ? An unrelated question - is there any reason why /var/qmail/control/virtualdomains isn't a CDB file ? John
