What are All the Ways a Programmer Could use PHP to Send an Email? [closed]

Question

I'm looking for a list of built in PHP functions that a programmer could use to send an email.

The obvious answer here is mail(), but I'm also looking for a list of functions someone might use to manually open a connection to an MTA, or spawn a process on the local machine which might in turn send an email using sendmail, postfix, etc.

The context here is I want to scan a large, unknown codebase for code that's sending out email (because we already located a call to mail(), and that's not doing it)

Answer 1

And as well as the backtick, also check for popen() and system execution functions... http://us2.php.net/manual/en/ref.exec.php

exec
passthru
proc_close
proc_get_status
proc_open
proc_terminate
shell_exec
system
` 

IMAP may be another depending on how PHP was configured... http://www.php.net/manual/en/ref.imap.php

   fsockopen is most likely the other one

Answer 2

fsockopen is most likely the other one.

Answer 3

IMAP may be another depending on how PHP was configured... http://www.php.net/manual/en/ref.imap.php

Answer 4

Sneaky way would be to turn off your local mail service and check your php error logs for the sendmail errors you get :)

This should stop php from being able to send emails locally

Answer 5

Just looking at the mail() docs, it looks like Pear::Mail would be a good candidate, or at least better.