SpamAssassin failures

[Todd Martin]

I'm in the process of evaluating mailscanner with SpamAssassin.
Currently I've enabled SpamAssasin in mailscanner.conf with a time
out of 120 seconds. SpamAssassin's spam threshold is at a '7'.

So far so good -- except I get the occasional spam message that
hasn't been labeled as spam. These are obvious spam to me so I tried
running the whole message (header and al) through spamassassin stand
alone (with -t option). The message scored 18 -- well above my
threshold. At first I thought something was broken, then I remembered
mailscanner.conf spamassassin timeout value.

That got me thinking about failure modes with mailscanner calling
spamassassin. Are there any known conditions that increase the chance
of the time out time being reached? Is there any other explanation of
mailscanner not letting spamassassin have a try at the spam?

My mail host is lightly loaded with new hardware so cpu load
shouldn't be the problem.

~Todd