[Mimedefang] High CPU Utilization

[Michael Pellegrino]

Here's my setup:

Pentium II, 256MB Ram, MD 2.30, SA 2.50, clamd 2.54, SPOOLDIR resides on a
RAM Disk, server does maybe 1000-1200 messages per day tops.  10 min slaves,
30 max.  timeout 90, busy timeout 300.  Suse Linux 8.1 (2.4.19).

When sendmail, md, and md-mx are all starting, I get a bunch of
mimedefang.pl processes starting up which is perfectly normal.  However,
they all show anywhere between 18-34% CPU utilization.  This lasts for about
a minute or so until they all drop to 0.  Also, they will jump up to that
range for each email message that it processes.  That seems a bit high.  Is
this normal?  This was never a problem before, but seems to coincide with
installing the recent sendmail security patch.  I'm pretty sure that's just
pure coincidence though.

We occasionally have brief spikes in email traffic, about 20-30 messages
over a 2-4 minute time period.  These are rare, but were never a problem
until recently.  We will get a few "ERR Filter timed out - system may be
overloaded" messages along with a lot of rejected emails (Milter:  data,
reject=451 4.7.1 Please try again later).

Any thoughts?  I could easily upgrade the server, but for the volume of
email this system should be just fine.  It just seems to me that the CPU
utilization on the mimedefang processes is a bit high.

Thanks in advance,

Mike