The FuzzyBlog! : PHP Code for Testing If an SMTP Address Exists

PHP Code for Testing If an SMTP Address Exists

This code taken from Mastering PHP 4.1 from Sybex. Chapter 10, Listing 10.7.

  /*
     * function email_works ($email)
     * args: $email (address to test)
     * We simulate an SMTP session to the server and use the 'RCPT TO'
     * to see whether the mail server will accept mail for this user.
     */

    function email_works ($email) {
        // get the list of mail serves for the user's host/domain name
        list ($addr, $hostname) = explode ("@", $email);
        if (!getmxrr ($hostname, $mailhosts))
            $mailhosts = array ($hostname); // if no MX records found
                                            // simply try their hostname
        $test_from = "me@domain.com"; // replace w/ your address
        for ($i = 0; $i < count ($mailhosts); $i++)
        {
            // open a connection on port 25 to the recipient's mail server
            $fp = fsockopen ($mailhosts[$i], 25);
            if (!$fp)
                continue;
            $r = fgets($fp, 1024);
            // talk to the mail server
            fwrite ($fp, "HELO " . $_SERVER['SERVER_NAME'] . "\r\n");
            $r = fgets ($fp, 1024);
            if (!eregi("^250", $r))
            {
                fwrite ($fp, "QUIT\r\n");
                fclose ($fp);
                continue;
            }
            fwrite ($fp, "MAIL FROM: <" . $test_from . ">\r\n");
            $r = fgets ($fp, 1024);
            if (!eregi("^250", $r)) 
            {
                fwrite ($fp, "QUIT\r\n");
                fclose ($fp);
                continue;
           }
            fwrite ($fp, "RCPT TO: <" . $email . ">\r\n");
            $r = fgets ($fp, 1024);
            if (!eregi("^250", $r))
            {
                fwrite ($fp, "QUIT\r\n");
                fclose ($fp);
                continue;
            }
            // if we got here, we can send email from $test_from to $mail
            fwrite ($fp, "QUIT\r\n");
            $r = fgets($fp, 1024);
            fclose ($fp);
            return true;
        }
        return false;
    }