Mail Troubles

[Robert Dinse <nanook@eskimo.com>]

     A mail loop occurred during the night that resulted in the corruption
of approximately 100 mailboxes.  With the exception of those boxes, mail
service is retored.

     A program is running which is processing those mailboxes.  They will
become available as each mailbox is restored.  I expect this process to
take 5-6 hours to complete.  Mail access may be somewhat slower than
normal during this interval.

     What appears to be happening is that someone who has procmail setup on
thier account has their account to expire.  This causes mail sent to their
account to bounce because the shell is then invalid for program execution.
A copy of that bounce gets forwarded to support.  Something, and I do not yet
know what occasionally causes this to loop.

     On the support account, procmail also is used to process incoming mail
and when the bounces fill up quota, sendmail seems to then put it back in
the mail spool rather than in the mailbox defined in procmail rules.  This
continues until the mail spool is full.

     I do not yet understand what causes it to loop and this is really key
to resolving the problem.