class.verifyEmail.php

<?php

/**
 * Class to check up e-mail
 *
 * @author Konstantin Granin <kostya@granin.me>
 * @copyright Copyright (c) 2010, Konstantin Granin
 */
class verifyEmail {

    /**
     * User name
     * @var string
     */
    private $_fromName;

    /**
     * Domain name
     * @var string
     */
    private $_fromDomain;

    /**
     * SMTP port number
     * @var int
     */
    private $_port;

    /**
     * The connection timeout, in seconds.
     * @var int
     */
    private $_maxConnectionTimeout;

    /**
     * The timeout on socket connection
     * @var int
     */
    private $_maxStreamTimeout;

    public function __construct() {
        $this->_fromName = 'noreply';
        $this->_fromDomain = 'localhost';
        $this->_port = 25;
        $this->_maxConnectionTimeout = 30;
        $this->_maxStreamTimeout = 5;
    }

    /**
     * Set email address for SMTP request
     * @param string $email Email address
     */
    public function setEmailFrom($email) {
        list($this->_fromName, $this->_fromDomain) = $this->_parseEmail($email);
    }

    /**
     * Set connection timeout, in seconds.
     * @param int $seconds
     */
    public function setConnectionTimeout($seconds) {
        $this->_maxConnectionTimeout = $seconds;
    }

    /**
     * Set the timeout on socket connection
     * @param int $seconds
     */
    public function setStreamTimeout($seconds) {
        $this->_maxStreamTimeout = $seconds;
    }

    /**
     * Validate email address.
     * @param string $email
     * @return boolean  True if valid.
     */
    public function isValid($email) {
        return (false !== filter_var($email, FILTER_VALIDATE_EMAIL));
    }

    /**
     * Get array of MX records for host. Sort by weight information.
     * @param string $hostname The Internet host name.
     * @return array Array of the MX records found.
     */
    public function getMXrecords($hostname) {
        $mxhosts = array();
        $mxweights = array();
        if (getmxrr($hostname, $mxhosts, $mxweights)) {
            array_multisort($mxweights, $mxhosts);
        }
        /**
         * Add A-record as last chance (e.g. if no MX record is there).
         * Thanks Nicht Lieb.
         */
        $mxhosts[] = $hostname;
        return $mxhosts;
    }

    /**
     * check up e-mail
     * @param string $email Email address
     * @return boolean True if the valid email also exist
     */
    public function check($email) {
        $result = false;
        if ($this->isValid($email)) {
            list($user, $domain) = $this->_parseEmail($email);
            $mxs = $this->getMXrecords($domain);
            $fp = false;
            $timeout = ceil($this->_maxConnectionTimeout / count($mxs));
            foreach ($mxs as $host) {
//                if ($fp = @fsockopen($host, $this->_port, $errno, $errstr, $timeout)) {
                if ($fp = @stream_socket_client("tcp://" . $host . ":" . $this->_port, $errno, $errstr, $timeout)) {
                    stream_set_timeout($fp, $this->_maxStreamTimeout);
                    stream_set_blocking($fp, 1);
//                    stream_set_blocking($fp, 0);
                    $code = $this->_fsockGetResponseCode($fp);
                    if ($code == '220') {
                        break;
                    } else {
                        fclose($fp);
                        $fp = false;
                    }
                }
            }
            if ($fp) {
                $this->_fsockquery($fp, "HELO " . $this->_fromDomain);
                //$this->_fsockquery($fp, "VRFY " . $email);
                $this->_fsockquery($fp, "MAIL FROM: <" . $this->_fromName . '@' . $this->_fromDomain . ">");
                $code = $this->_fsockquery($fp, "RCPT TO: <" . $user . '@' . $domain . ">");
                $this->_fsockquery($fp, "RSET");
                $this->_fsockquery($fp, "QUIT");
                fclose($fp);
                if ($code == '250') {
                    /**
                     * http://www.ietf.org/rfc/rfc0821.txt
                     * 250 Requested mail action okay, completed
                     * email address was accepted
                     */
                    $result = true;
                } elseif ($code == '450' || $code == '451' || $code == '452') {
                    /**
                     * http://www.ietf.org/rfc/rfc0821.txt
                     * 450 Requested action not taken: the remote mail server
                     *     does not want to accept mail from your server for
                     *     some reason (IP address, blacklisting, etc..)
                     *     Thanks Nicht Lieb.
                     * 451 Requested action aborted: local error in processing
                     * 452 Requested action not taken: insufficient system storage
                     * email address was greylisted (or some temporary error occured on the MTA)
                     * i believe that e-mail exists
                     */
                    $result = true;
                }
            }
        }
        return $result;
    }

    /**
     * Parses input string to array(0=>user, 1=>domain)
     * @param string $email
     * @return array
     * @access private
     */
    private function _parseEmail(&$email) {
        return sscanf($email, "%[^@]@%s");
    }

    /**
     * writes the contents of string to the file stream pointed to by handle $fp
     * @access private
     * @param resource $fp
     * @param string $string The string that is to be written
     * @return string Returns a string of up to length - 1 bytes read from the file pointed to by handle.
     * If an error occurs, returns FALSE.
     */
    private function _fsockquery(&$fp, $query) {
        stream_socket_sendto($fp, $query . "\r\n");
        return $this->_fsockGetResponseCode($fp);
    }

    /**
     * Reads all the line long the answer and analyze it.
     * @access private
     * @param resource $fp
     * @return string Response code
     * If an error occurs, returns FALSE
     */
    private function _fsockGetResponseCode(&$fp) {
	$reply = stream_get_line($fp, 1);
	$status = stream_get_meta_data($fp);
	if ($status['unread_bytes']>0)
	{
		$reply .= stream_get_line($fp, $status['unread_bytes'],"\r\n");
	}

        preg_match('/^(?<code>[0-9]{3}) (.*)$/ims', $reply, $matches);
        $code = isset($matches['code']) ? $matches['code'] : false;
        return $code;
    }

}

?>