[Mimedefang] "cmd read returned"

[Joseph Brennan]

I haven't posted in a little while. Mimedefang runs so smoothly
and I haven't been fast enough to answer questions I know. But now 
I am puzzled.

We've moved from Solaris to SE Linux RHEL 6, which means we've moved
from compiling software to using packages. I am trying to go with the
flow. I know it's Sendmail 8.14.4 and Mimedefang 2.78.

We had a Spamassassin incompatibility. We have used the PDFInfo.pm
plugin for years and configured the new Spamassassin in the .pre file
to use it, but the Spamassassin package from Yum does not include
PDFINfo.pm (huh?) so not surprisingly we got this: 

 Slave 11 stderr: plugin: failed to parse plugin (from @INC): Can't
 locate Mail/SpamAssassin/Plugin/PDFInfo.pm in @INC (@INC contains:...

We'll deal with that. What I am writing about is Mimedefang's followup
to that, which was:

sendmail[3600]: u4N5l72x003600: milter_sys_read(mimedefang): cmd read
returned 0, expecting 5
sendmail[3600]: u4N5l72x003600: Milter (mimedefang): to error state

Thanks to Gmail's practice of sending to one RCPT at a time, we had
over a dozen identical messages (same Message-ID). They all got the
PDFInfo.pm error but the first ones continued and were sent out after
about 4 seconds. After those slow successes, the later ones failed;
for those sendmail logged the 2 errors shown, and at that same time,
the multiplexor died, and senders got "Please try again later", 
logged 7 or 8 seconds after the "from=" log line.

I see from archived messages (nine years ago!) this could be caused by
mismatched milter libraries, sendmail and mimedefang. I would like to
believe that the Red Hat people have sendmail and mimedefang linked to
the same library, although I am always an optimist. Is there any other
cause we can look for?

I should add that that we went a few weeks on the new system without
ever seeing this. Something unusual happened. My main concern is to
avoid having the multiplexor die. I have of course removed PDFInfo
from the Spamassassin configuration, pending testing and installing
the plugin in the new environment-- so that particular cause will
not recur.


--Joseph Brennan
Columbia University