My postfix connection is reporting an error this morning:
Feb 15 09:33:23 helo postfix/cleanup[45022]: warning: connect to mysql server Can't connect to MySQL server on '' (110)
When I try to connect to MySQL manually, it seems to work so long as I don't specify a host. But when I do specify the localhost, it cannot connect. It just times out.

The odd thing is that this works:
mysql -u postfix_user -p -h localhost
But this does not:
mysql -u postfix_user -p -h
I checked my /etc/hosts file and localhost does resolve to so those two commands should work exactly the same.

No errors are shown in the syslog or the mysql logs.

A number of different google searches seem to suggest checking the firewall settings. Outside of iptables, I don't have anything else installed (at least that I know of).

Can anyone offer a clue?