Undeliverable Mail, using mail()

[jmarco]

when sending email via the mail($to, $title, $message, $headers) function, how do you know if the recipient in $to got the message? I need to know if the message was undeliverable or not.

Right now it just sends it and if it's not an existing email address I never know.

[LordShryku]

Well, if you are using *nix, you can get an email back from the server that denied it. check with the proper mail function in the mail address you setup in php.ini