i use simscan to scan every mail on one of my mailservers.
i don’t often restart my servers, so sometime i get the following error in my smtp log file.

2007-04-20 12:11:13.004232500 connect(): No such file or directory

most of the time this happens when clamd or spamassassin is not started. normally this should happen on the restart.

in my case
clamd &
solved the issue.