[Mailman-Users] Bounce processing questions (feature, or bug?)

[Hank van Cleef]

The background scenario is that I have been experiencing the "now you
see it/now you don't" big-consumer-internet mail service spam
blocking.  This week it is Verizon.net.  

Basically, mail to verizon.net addresses failed and bounced for a 24
hour period on the 12th.  Service appeared to have been restored on
the 13th.  Again, yesterday (the 18th), Verizon quit receiving mail
again.  The log message being shown by sendmail is of the the form:

Jun 19 10:49:00 julie sendmail[16973]: [ID 801593 mail.info]
m5JGmxNk016971: to=<customer at verizon.net>,
ctladdr=<vancleef at julie.lostwells.net> (101/10), delay=00:00:00,
xdelay=00:00:00, mailer=esmtp, pri=121428, relay=relay.verizon.net.
[206.46.232.11], dsn=5.0.0, stat=Service unavailable

For the four days June 13-17, mail went verizon.net normally,
dsn-2.0.0, stat=Sent 

Two Verizon users have contacted me and told me that they had received
no mail from our list since the 11th; that they had contacted Verizon
support, and had been told that Verizon was not blocking or dumping
our list mails.  Both users are sufficiently knowledgeable to have
looked for shunting to a "spam" or "bulk" file.  I wrote a private
e-mail to one user giving log details for him to use.  That e-mail
bounced back sky high, and the bounce message made clear that Verizon
has a spam block on my IP.  The log message was another dsn=5.0.0
stat=Service unavailable.

I decided to change the bounce processing so that if this "Service
unavailable" bouncing continued into a second day, the affected
Verizon users would get bounce-trapped, and I'd see the triggering
bounce messages.  Accordingly I changed:

Bounce score from 3.0 to 2.0
Discard period from 2 to 4 days
Number of warnings from 3 to 2
Notification interval left at 7 days

I've just double checked to be sure that the numbers in the window are
2.0, 4, 2, and 7.

This did exactly what I wanted, and I've got about thirty bounce
messages showing 5.7.1 security bounces, some of which I've forwarded
(via another IP) to affected Verizon users for their use in dealing
with the ISP.

However, I've also gotten about fifty other bounce disables on the 2.0
score.  Some investigation shows that affected users had accumulated
two bounces several months ago, but none since.  From what I see in
the bounce logs still in my rotation, it appears that the bounce
processor did not sense that these bounces were very stale (over 90
days, when I've specified 4), but simply operated on my reducing the
score from 3.0 to 2.0.  A couple of users have forwarded back the
bounce e-mail they received and have noted the "last bounce dates" in
March-April. 

Mailman version is 2.1.9, local build with Python 2.4.3 on Solaris 9.

Hank