Zimbra mail suddenly stopped working

After a couple of days with no mail I decided that something must be wrong. A quick check of the logs showed a problem.

I tailed the log file while I sent myself an email from another account:

tail -f /var/log/mail.log

The mail tried to be delivered but there was an error occurring:

127.0.0.1[127.0.0.1]:10024: Connection refused

It seems the Zimbra mailserver was not accepting connections. This was easily resolved with a quick restart.

zmcontrol stop

zmcontrol start