Comment 16 for bug 56235

I should have included the following information:

Ubuntu Server v7.10
Installed inside a VMware instance.

Basic install (just openssh and internet mail).

One of the clues (which didn't help me solve it, but gave me some places to look) was: https://bugs.launchpad.net/ubuntu/+source/postfix/+bug/42947

The dpkg remove postfix and dpkg purge postfix didn't fully work. This might have been the result of some dependency issues with dovecot (which is where my problems were).

Tim