...
If you're using spamd, you should be aware that spamc will only pass messages under 250k in size to spamd. This is a built-in limit that you can override using the "-s" option on the command-line. Refer to the spamc man page for more details.
By default, procmail will spawn a new process for every email received; if your receive a lot of messages at a time (e.g., when you use fetchmail), procmail may create too many SpamAssassin processes. Just use a lock so procmail handles messages one at a time:
| No Format |
|---|
:0fw: spamassassin.lock
| spamassassin
|
See also OutOfMemoryProblems.