[Sysadmin] Tracking Bounces Problem

[Dean Mah]

As you may have noticed, I tried adding a 'content' filter to postfix.
(postfix allows you to 'hook' filters into the mail process at various
points.)  Ran into the same problem as when I tried to add the
recipient into the headers during the cleanup phase, i.e., a list of
recipients and one message.

So I'm trying to add something into the smtp process that handles the
actual delivery.  I figured there I'd have an individual recipient
matched to an individual message and that I could inject a header at
that time.  However, from what I get by skimming:

   http://cr.yp.to/smtp.html

this isn't the case.  The summary is that once the client connects to
the destination SMTP server, the client can pass multiple 'RCPT TO'
commands to the server (one for each recipient at that server) and one
'DATA' command containing the message.  Which means that I still don't
have direct access to individual recipients if the addresses are
grouped by domain.  I would assume that this is how Mailman is
conversing with the relays themselves, i.e., sending multi-recipient
lists and a single message to save bandwidth.

So.... I can:

1) Print the entire list of recipients to the server.  This would
   compromise privacy if there were multiple recipients at a site,
   e.g. people with m.e.o addresses.

2) Generate or find a unique sequence number and add it to the
   headers.  Then save the sequence number and recipient list to a
   file for later lookup.

Anyone else have any ideas?

Dean