bizarre log/bounce discrepancy - please help

[stephenrs]

hi,

preamble: i'm managing a large mailing list, and need to produce detailed stats about bounces, and other performance parameters. the list manager i'm using (phplist) natively uses a destination (return-to) mailbox file and custom-generated headers to track bounces, but i'd prefer to rely on the postfix maillog, so i've been keeping a close eye on both, and comparing the results.

so far, the two bounce-tracking methods have compared pretty closely, with the maillog being more acurate, and reporting slightly more bounces because some MTAs are stripping the custom headers before bounces reach the bounce mail file. However, on my last mailing the results were radically different and a bit disturbing.

with a mailing to about 60,000 addresses - all to AOL users, the bounce mailbox showed about 22,000 bounces, which seemed reasonable. The maillog, however, only shows about 100 undeliverable (not "sent") messages.

Looking at a single example, the maillog shows:

Jun 99 15:05:48 <some-text> postfix/smtp[12345]: <a message ID>: to=<someuser@aol.com>, relay=a-relay.aol.com[12.34.567.890], delay=0, status=sent (250 OK)

for the identical address, the returned mail file shows the standard:

...
----- The following addresses had permanent fatal errors -----
<the-same-user@aol.com>
...

can someone pleeease explain to me how this disagreement is possible? either i'm missing something, or something has gone horribly wrong. was this example message actually delivered, or not?

in case it matters to you, the mailing list is not advertising or SPAM.

thanks.

 

[ericbrunson]

The logs only know when the mail is refused by the primary mail exchanger. There can be many, many reasons the mail bounces after it is initially accepted.

 

[stephenrs]

ok, i see. thanks.

so this must mean that logs cannot be fully relied upon for tracking bounces i initially thought that logs would be the best source of information about the fate of outbound emails, but i see that there are a few things i still need to learn about the smtp chain of events...

have any suggestions for a foolproof way to track outbound mail?

are message-ids preserved in headers?