[Mimedefang] timeout before data read?

[Rich West]

Quite suddenly, and consistently, today at around noon, I started seeing 
the following messages in my maillog, and the load average on the system 
went through the roof (load average shot up beyond 22!) shortly afterwards.

Nov 17 15:02:51 cranium sm-mta[24072]: iAHK1XJR024072: Milter 
(mimedefang): timeout before data read
Nov 17 15:02:51 cranium sm-mta[24072]: iAHK1XJR024072: Milter 
(mimedefang): to error state
Nov 17 15:02:51 cranium sm-mta[24072]: iAHK1XJR024072: Milter: data, 
reject=451 4.3.2 Please try again later
Nov 17 15:02:51 cranium sm-mta[24072]: iAHK1XJR024072: 
to=<user at myhost.com>, delay=00:01:01, pri=32062, stat=Please try again later

Now, if I bring down both mimedefang and sendmail and bring it back up 
again, I can get some mail to come through, but very little before it 
starts spitting out these errors again.

And, it seems, that mimedefang keeps being forced to spawn a new 
process, leaving the old one around to spin its wheels, and the new 
process will generate the same error, and then spawn a new process 
because of the failure, and so on and so on, becoming a very fast and 
sick cycle. :(

I'm pretty much at a loss as to what could be the cause since neither 
mimedefang nor sendmail have been rebuilt in quite a while (I am running 
the latest mimedefang and the latest sendmail, of course).  And no 
changes have been put in to place in the mimedefang-filter either. :(

Right now, I am limping by only by watching the maillog, seeing a 
failure of a slave, and restarting mimedefang as a whole...  Of course, 
I can't keep that up forever..

-Rich