I run a webserver where I allow users the use of PHP3 for their websites.

The issue I have run accross that is more of an annoyance than anything else, but can fill the postmaster's inbox fairly quickly if I'm not careful.

If a user sets up a mail() function and it tries to send to nobody (ie: no outgoing address), I get mail in the postmaster's inbox stating that a message with a malformed recipient address was sent from www-data (the user apache runs under), and was therefore killed.  There is no information as to where this message originated, etc.

It would be nice if the mail() function automatically stuck a URL for the submitting page either on the end of the e-mail or hidden in the headers somewhere:

Sent from: http://www.somewhere.com/~user/brokenmailer.php3

This way, if I do get messages bounced to postmaster, I can easily track down the offending user and get them to delete or fix the script.

If there's a way to do this already, and I'm just oblivious to it, please point me in the right direction.  The dead letters are starting to drive me nuts.  :)