I just rebooted the server and it seemed to come up okay. However, upon opening SAC I noticed that SMTPD was not running. Here's what the log says:
ERROR SMTP Relay (SMTPD Relay Pr) 01.13.06 17:31:57
[OM.DMON 2171] The SMTP Relay could not listen on port 25.
The only thing I changed was installing TM VirusWall. Is that interfering with port 25?