dovecot errors, can't disable Mail Service

[spookybathtub]

I'm running Lion Server 10.7.3. I have no need for a mail server, and I don't know why it's running in the first place. But when I try to disable it, using either Server.app or Server Admin, it turns itself right back on a few seconds later.
Additionally, my system.log is getting filled with these errors several times per second:
Apr 24 23:43:00 radio dovecot[20040]: lda: Error: userdb lookup: connect(/var/run/dovecot/auth-userdb) failed: Socket operation on non-socket
Apr 24 23:43:00 radio dovecot[20040]: lda: Fatal: Internal error occurred. Refer to server log for more information.

I noticed that dovecot's parent is pipe, whose parent is master, which is being started by org.postfix.master.plist in launchd. I'm hesitant to simply unload that Launch Daemon, because I don't know if it will affect anything else.
By the way, radio is the first part of my domain name, so I guess that's why it's in the logs.