Where does bounced mail from php scripts go?

[StewardManscat]

Slackware 10.x Dedicated server. Postfix.

Running vbulletin. When scripts send mail to users, and the mail bounces, I would like to know. Vbulletin scripts boil down to the mail() function, which I understand sends as "[e-mail]".

Using webmin and postfix, I seem unable to trap or redirect the bounced mail, so I can see which of my users is "AWOL".

My host is now telling me this is impossible on any system

I can't believe that! Any clues for me? Any hints on where to go on a hunt? Is this outside the scope of php? Should I be concentrating on postfix mail config? Or some other config?

Please and thank you.

[MarkR]

Bounced mail goes to the return path for the user who sent the mail. Normally on a Unix-like system, this is the user which the web server runs as typically "nobody", "web", or "www-data".

Therefore, it drops into their mailbox if they have one, and probably goes to a catch-all mailbox (root's for example) if they don't.

If neither the user, nor the catch-all have a working mailbox, then it is a "triple bounce" and is thrown away:

• Single bounces go to the envelope sender
• Double bounces go to the catch-all mailbox (root, or mailer-daemon or something) - this is often an alias
• Triple bounces get thrown away as there is nowhere to deliver them to.

Mark