PHP mail() doesn't work [duplicate]

Question

I want to script a simple registration form with activation mail and so on. But for some reason mail() doesn't send the emails, or my 3 different email accounts (hotmail,gmail,yahoo) don't receive them and therefore don't even put them in the spam folder.

Code:

<?php
    $mailto = '[email protected]';
    $subject = 'the subject';
    $message = 'the message';
    $from = '[email protected]';
    $header = 'From:'.$from;

    if(mail($mailto,$subject,$message,$header)) {
        echo 'Email on the way';
    }
?>

Everytime it outputs 'Email on the way' so mail() returns true, right? I really don't get it, I've even tried to turn off my little snitch (although I didn't block SMTP).

Answer 1

See this article by Jeff Atwood.

In short: Just because your code has handed the e-mail to a Mail Transfer Agent, it doesn't mean it will be delivered. Yes, mail() returning true means "accepted for delivery" - which means "Looks like an e-mail, I'll try to deliver this", not "It is delivered". Even the manual for mail() says:

It is important to note that just because the mail was accepted for delivery, it does NOT mean the mail will actually reach the intended destination.

Soooo: check your MTA (is the e-mail sent from your local computer?), try to send to a local address (if the address is local, does it get delivered?), try to send an e-mail from your mail client, using the same settings as your PHP script, try to send to a smaller mail-hoster which allows you tu switch off antispam (is it delivered outside your network?). Also, read that article, and check the points mentioned there.

Answer 2

Maybe your server is not configured to handle mail().

<?php
    print phpinfo();  
?>

and look at sendmail_path

Answer 3

You may need to add correct end of line characters to the Headers. It may be \n or \r\n