If you see messages like this:

{{{spamd[3279]: prefork: server reached --max-clients setting, consider raising it}}}

You'll probably try raising the {{{--max-clients}}} setting, only to find that that switch does not exist.   This was a typo; the correct settting is called {{{--max-children}}}.

[[http://mail-archives.apache.org/mod_mbox/spamassassin-users/200601.mbox/%3C43CE9A46.3030607@evi-inc.com%3E|See this mail from Matt Kettler]] for more details.

[[http://issues.apache.org/SpamAssassin/show_bug.cgi?id=4586|This bug]] was fixed in SA 3.1.1.