[Mimedefang] Reject 451 (Please try again later) messages

[Bill Randle]

In the last few days I've seen a flood of "Milter: data, reject=451 
4.7.1 Please
try again later" messages in the mail logs. My guess was this was due to
spamassassin taking too long to filter the mail. Now I'm not so sure. I 
still
think it's related to SpamAssassin, because if I comment out that section of
mimedefang-filter I don't get the warnings (or at least very few of them).

In looking as the log file a little closer, I noiced something strange that
perhaps someone can shed light on. Here's an example set of entries for a
message that had this reject:

  [root at outlaw2 mail]# grep h5IITIVe002002 info
  Jun 18 11:29:25 outlaw2 sendmail[2002]: h5IITIVe002002: 
from=<Torriic at sapo.pt>,
    size=3251, class=0, nrcpts=1, msgid=<mugdsop at sapo.pt>, proto=SMTP, 
daemon=MTA,
    relay=c-66-56-36-72.atl.client2.attbi.com [66.56.36.72]
  Jun 18 11:30:08 outlaw2 mimedefang.pl[2019]: 
MDLOG,h5IITIVe002002,mail_in,,,
    <torriic at sapo.pt>,<lutton at outlawnet.com>,lutton It worked for me - 
it will work
    for you
  Jun 18 11:30:25 outlaw2 sendmail[2002]: h5IITIVe002002: Milter 
(mimedefang):
    to error state
  Jun 18 11:30:25 outlaw2 sendmail[2002]: h5IITIVe002002: Milter: data,
    reject=451 4.7.1 Please try again later
  Jun 18 11:30:25 outlaw2 sendmail[2002]: h5IITIVe002002: 
to=<lutton at outlawnet.com>,
    delay=00:01:03, pri=30229, stat=Please try again later
  Jun 18 11:30:43 outlaw2 mimedefang.pl[2019]: 
MDLOG,h5IITIVe002002,spam,23.177,,
    <torriic at sapo.pt>,<lutton at outlawnet.com>,lutton It worked for me - 
it will work
    for you
  Jun 18 11:30:43 outlaw2 mimedefang.pl[2019]: filter: h5IITIVe002002:  
discard=1
  Jun 18 11:30:43 outlaw2 mimedefang[2013]: h5IITIVe002002: Discarding 
because filter
    instructed us to

1. The first entry shows an incoming mail, which is logged to the info 
file for creating
   graphdefang plots
2. mimedefang goes to an error state (have no idea why) and causes 
sendmail to log
   the reject
3. here's the confusing part: it looks like sendmail is sending a 
"Please try again later"
   message to the recipient of the mail, rather than the sender! Is that 
what the log entry
   is telling me, or am I just confused?
4. mimedefang calls spamassassin, which tags it as spam, causing the 
milter to discard it

So, in addition to my question in #3 above, it would appear that 
mimedefang got some kind
of error, and signal the reject, yet kept on processing the message. Is 
that correct?
Can someone explain what's *really* going on here?

mimedefang-2.34-BETA-5
Mail-Spamassassin-2.60
sendmail-8.12.9

    -Bill Randle
    billr at neocat.org