Sendmail remote connection refused

How to enable sendmail to accept remote connections. By default most distributions (or when compiling sendmail yourself) will only allow local connections for security reasons.

Dovecot dead but subsys locked error

When you restart dovecot, if it won’t start up again it’s likely the process crashed on startup but left the subsys lockfile in place. This prevents dovecot from starting up again. If you run /etc/init.d/dovecot status and get the error message "dovecot dead but subsys locked" then you have this problem.

Spamassassion connection refused

If you get a message like the one following, then you are filtering emails through spamassasin using /usr/bin/spamc but the spamassassin service is not running. connect(AF_INET) to spamd at failed, retrying (#1 of 3): Connection refused.