[Mailman-Users] Sporadic, fractional non-delivery

[Jason LaMar]

We have an on-campus list with about 1,900 student subscribers that has been
functioning properly for months. Recently, however, an extremely small
percentage of students -- about 1% that we're aware of -- have stopped
getting messages from the list.

Here are some of the specifics ...

1. Mailman and the MTA (Sendmail) both reside on the same well-configured
Red Hat Linux ES server, which serves as our primary on-campus e-mail
server, too.

2. Doing grep on specific account names through all the Mailman logs hasn't
turned up any issues.

3. All impacted students are receiving "normal" (non-Mailman) messages just
fine from the same on-campus domain, which (again) is driven by the same
Sendmail instance.

4. No differences can be found at the Linux account level -- directory
permissions, user configuration, etc. -- between those who are receiving the
messages and those who aren't.

5. The impacted account names have been confirmed to reside in the Mailman
config.pck file and via the Web GUI Membership Management screen with
typical (non-digest) delivery preferences set.

I should note that some of these students are automatically forwarding their
University e-mail to an off-campus account -- like Gmail or Hotmail -- and
obviously that introduces another layer of message filtering. But many of
these students are using on-campus IMAP or POP e-mail resources only, and a
spot check immediately after a message is distributed via Mailman reveals
that they still aren't getting anything from the list.

Any ideas to help our investigation on the Mailman and/or Sendmail side? Is
there some extra verbose logging that could be turned on?



Thanks,

Jason

_________________________

Jason LaMar
Director of Information Services
Ohio Wesleyan University | Delaware, OH 43015
AIM/Yahoo IM: jasonrlamar | MSN/Google Talk: jasonrlamar at gmail.com
Tel: 740-368-3131 | Fax: 740-368-3272 | Web: http://www.owu.edu/