Resolution of "very urgent problem with MailScanner & Postfix..."

[Ron E.]

I thought I had better let everyone know what I cam up with after all
this.

Quick recap: Running MailScanner & Postfix for months, suddenly earlier
this week a backlog started accumulating and could only be halted by
temporarily stopping the incoming postfix, letting MailScanner catch up,
then starting it back up again. Found out that this was fixed in the
latest stable build of MailScanner but didn't upgrade yet. (Note that
along with the backlog was the problem where duplicate truncated
messages were being delivered, discussed earlier on this list. - "still
being delivered" error, etc)

Anyway, no problems until late in the week when another backlog began
accumulating. Didn't mess around at this point, but upgraded.
Unfortunately the backlog continued to grow until again I stopped the
incoming postfix to allow mailscanner to catch up. Did things like turned
off RBLs do help this along. Started incoming postfix again at which point
another backlog immediately started accumulating. Inspection of the logs
showed mailscanner taking quite awhile on each message. Various
performance settings tweaked, message batch reduced to 10 from 100, and
changed "Max Normal Queue Size" to 500 (from 5000).

Note that throughout all this the other oddity was that a service
MailScanner restart would stop everything fine but then MailScanner would
not start - another service MailScanner start would be needed to get it
going again. I finally noticed what I should have noticed originally -
there were too many mailscanner processes running (I had 5 max children
set). I believe this may have been why I was still having a problem with
the "still being delivered" error. I killed those of course and that
handled the starting problem.

Next I started running debug mode, again something I should have done
earlier. Found that razor, pyzor and dcc were not working. Razor seemed to
be causing the biggest delay, followed by pyzor. Dcc was just erroring.
Found that despite doing the usual server discovery for razor & pyzor, the
servers were not updating for some reason. Managed to get ahold of the
correct server IPs and then all of a sudden pyzor & razor started working.

Hopefully all this will be of use to someone else who may run into a
similar situation.

The last unresolved thing is dcc - if anyone has any ideas on fixing this,
I'd be very interested. The errors I get are:

no executable dccproc found
DCCifd is not available: no r/w dccifd socket found

I checked, though, and there is an executable dccproc in
/usr/local/bin/dccproc

Perhaps spamassassin just doesn't know where to find dccproc?

I installed the latest version but no change.

In any case, thanks to all who assisted, particularly Julian.

Regards,

Ron