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Aug 27th, 2008

Re: check if email address is correct without sending email?

Click to Expand / Collapse Quote originally posted by pritaeas ...

Some companies do not like such access and will report it is a cracking attempt. Maybe it's not as big an issue as it was several years ago, but there are ignorant companies out there. I didn't understand it either, but obviously it happens.

Well, sorry that happened to you.

digital-ether

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Aug 27th, 2008

Re: check if email address is correct without sending email?

hope i will not happen with me

nikesh.yadav

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Sep 7th, 2008

Re: check if email address is correct without sending email?

Hi digital-ether,

Click to Expand / Collapse Quote originally posted by digital-ether ...

I wrote a class that you can use for the validation with SMTP. It will only work on Linux as Windows doesn't have the getmxrr() function or other DNS functions.
If needed on windows, one can replace the DNS functions with the Pear Net_DNS library.
http://pear.php.net/package/Net_DNS

Thanks for the SMTP validation class, I've made a few of tweaks, and thought I'd share with everyone.

1) The new line terminator should include a carriage return (\r), otherwise it won't work with some Windows MTAs, eg. Hotmail.
2) Now checks MX servers in order of priority.
3) fread should be executed before fwrite, as some MTAs with anti-spam mechanisms will close the connection (and blacklist the client) if the HELO is sent before the server's greeting.
4) Consider code 451 and 452 as success, as if the MTAs uses greylisting (451) it will take a while before we can really verify (comment this bit out if not needed), and if there's a lack of space on the MTA it should be temporary (452), and resolved eventually, but the mailbox exists.
5) Using explode(' ', $code) doesn't work in all cases, as some MTAs use a '-'. Replaced with substr.

Adnan

php Syntax (Toggle Plain Text)
<?
/**
 * Validate an Email Address Via SMTP
 * This queries the SMTP server to see if the email address is accepted.
 * @copyright http://creativecommons.org/licenses/by/2.0/ - Please keep this comment intact
 * @author gabe@fijiwebdesign.com
 * @contributors adnan@barakatdesigns.net
 * @version 0.1a
 */
class SMTP_validateEmail {
 
	var $sock;
 
	var $user;
	var $domain;
	var $port = 25;
	var $max_conn_time = 30;
	var $max_read_time = 5;
 
	var $from_user = 'user';
	var $from_domain = 'localhost';
 
	var $debug = false;
 
	function SMTP_validateEmail($email = false, $sender = false) {
		if ($email) {
			$this->setEmail($email);
		}
		if ($sender) {
			$this->setSenderEmail($sender);
		}
	}
 
	function setEmail($email) {
		list($user, $domain) = explode('@', $email);
		$this->user = $user;
		$this->domain = $domain;
	}
 
	function setSenderEmail($email) {
		list($user, $domain) = explode('@', $email);
		$this->from_user = $user;
		$this->from_domain = $domain;
	}
 
	/**
	* Validate an Email Address
	* @param String $email Email to validate (recipient email)
	* @param String $sender Senders Email
	*/
	function validate($email = false, $sender = false) {
		if ($email) {
			$this->setEmail($email);
		}
		if ($sender) {
			$this->setSenderEmail($sender);
		}
		// retrieve SMTP Server via MX query on domain
		$result = getmxrr($this->domain, $hosts, $mxweights);
 
		// retrieve MX priorities
		for($n=0; $n < count($hosts); $n++){
			$mxs[$hosts[$n]] = $mxweights[$n];
		}
 
		asort($mxs);
 
		// last fallback is the original domain
		array_push($mxs, $this->domain);
 
		$this->debug(print_r($mxs, 1));
 
		$timeout = $this->max_conn_time/count($hosts);
 
		// try each host
		while(list($host) = each($mxs)) {
			// connect to SMTP server
			$this->debug("try $host:$this->port\n");
			if ($this->sock = fsockopen($host, $this->port, $errno, $errstr, (float) $timeout)) {
				socket_set_blocking($this->sock, false);
				break;
			}
		}
		$code = substr($reply, 0, 3);
		if($code != '220') {
			// MTA gave an error...
			return false;
		}
 
		// did we get a TCP socket
		if ($this->sock) {
			$resp = '';
			$start = $this->microtime_float();
			while(1) {
				$reply = fread($this->sock, 2082);
				$resp .= $reply;
				if (($resp != '' && trim($reply) == '') 
				|| ($this->microtime_float() - $start > $this->max_read_time )) {
					break;
				}
			}
 
			// say helo
			$this->send("HELO ".$this->from_domain);
			// tell of sender
			$this->send("MAIL FROM: <".$this->from_user.'@'.$this->from_domain.">");
			// ask of recepient
			$reply = $this->send("RCPT TO: <".$this->user.'@'.$this->domain.">");
			// quit
			$this->send("quit");
			// close socket
			fclose($this->sock);
			// get code and msg from response
			$code = substr($reply, 0, 3);
 
			if ($code == '250') {
				// you received 250 so the email address was accepted
				return true;
			} elseif ($code == '451' || $code == '452') {
				// you received 45[12] so the email address was greylisted (or some temporary error occured on the MTA) - so assume mailbox exists
				return true;
			}
 
		}
 
		return false;
	}
 
 
	function send($msg) {
		fwrite($this->sock, $msg."\r\n");
 
		$resp = '';
		$start = $this->microtime_float();
		while(1) {
			$reply = fread($this->sock, 2082);
			$resp .= $reply;
			if (($resp != '' && trim($reply) == '') 
			|| ($this->microtime_float() - $start > $this->max_read_time )) {
				break;
			}
		}
 
		$this->debug(">>>\n$msg\n");
		$this->debug("<<<\n$resp");
 
		return $resp;
	}
 
	/**
	 * Simple function to replicate PHP 5 behaviour. http://php.net/microtime
	 */
	function microtime_float() {
		list($usec, $sec) = explode(" ", microtime());
		return ((float)$usec + (float)$sec);
	}
 
	function debug($str) {
		if ($this->debug) {
			echo $str;
		}
	}
 
}
?>
<?
/**
 * Validate an Email Address Via SMTP
 * This queries the SMTP server to see if the email address is accepted.
 * @copyright http://creativecommons.org/licenses/by/2.0/ - Please keep this comment intact
 * @author gabe@fijiwebdesign.com
 * @contributors adnan@barakatdesigns.net
 * @version 0.1a
 */
class SMTP_validateEmail {

	var $sock;

	var $user;
	var $domain;
	var $port = 25;
	var $max_conn_time = 30;
	var $max_read_time = 5;
	
	var $from_user = 'user';
	var $from_domain = 'localhost';
	
	var $debug = false;

	function SMTP_validateEmail($email = false, $sender = false) {
		if ($email) {
			$this->setEmail($email);
		}
		if ($sender) {
			$this->setSenderEmail($sender);
		}
	}
	
	function setEmail($email) {
		list($user, $domain) = explode('@', $email);
		$this->user = $user;
		$this->domain = $domain;
	}
	
	function setSenderEmail($email) {
		list($user, $domain) = explode('@', $email);
		$this->from_user = $user;
		$this->from_domain = $domain;
	}
	
	/**
	* Validate an Email Address
	* @param String $email Email to validate (recipient email)
	* @param String $sender Senders Email
	*/
	function validate($email = false, $sender = false) {
		if ($email) {
			$this->setEmail($email);
		}
		if ($sender) {
			$this->setSenderEmail($sender);
		}
		// retrieve SMTP Server via MX query on domain
		$result = getmxrr($this->domain, $hosts, $mxweights);

		// retrieve MX priorities
		for($n=0; $n < count($hosts); $n++){
			$mxs[$hosts[$n]] = $mxweights[$n];
		}

		asort($mxs);

		// last fallback is the original domain
		array_push($mxs, $this->domain);
		
		$this->debug(print_r($mxs, 1));
		
		$timeout = $this->max_conn_time/count($hosts);
			
		// try each host
		while(list($host) = each($mxs)) {
			// connect to SMTP server
			$this->debug("try $host:$this->port\n");
			if ($this->sock = fsockopen($host, $this->port, $errno, $errstr, (float) $timeout)) {
				socket_set_blocking($this->sock, false);
				break;
			}
		}
		$code = substr($reply, 0, 3);
		if($code != '220') {
			// MTA gave an error...
			return false;
		}

		// did we get a TCP socket
		if ($this->sock) {
			$resp = '';
			$start = $this->microtime_float();
			while(1) {
				$reply = fread($this->sock, 2082);
				$resp .= $reply;
				if (($resp != '' && trim($reply) == '') 
				|| ($this->microtime_float() - $start > $this->max_read_time )) {
					break;
				}
			}

			// say helo
			$this->send("HELO ".$this->from_domain);
			// tell of sender
			$this->send("MAIL FROM: <".$this->from_user.'@'.$this->from_domain.">");
			// ask of recepient
			$reply = $this->send("RCPT TO: <".$this->user.'@'.$this->domain.">");
			// quit
			$this->send("quit");
			// close socket
			fclose($this->sock);
			// get code and msg from response
			$code = substr($reply, 0, 3);
			
			if ($code == '250') {
				// you received 250 so the email address was accepted
				return true;
			} elseif ($code == '451' || $code == '452') {
				// you received 45[12] so the email address was greylisted (or some temporary error occured on the MTA) - so assume mailbox exists
				return true;
			}
		
		}
		
		return false;
	}


	function send($msg) {
		fwrite($this->sock, $msg."\r\n");

		$resp = '';
		$start = $this->microtime_float();
		while(1) {
			$reply = fread($this->sock, 2082);
			$resp .= $reply;
			if (($resp != '' && trim($reply) == '') 
			|| ($this->microtime_float() - $start > $this->max_read_time )) {
				break;
			}
		}

		$this->debug(">>>\n$msg\n");
		$this->debug("<<<\n$resp");
		
		return $resp;
	}
	
	/**
	 * Simple function to replicate PHP 5 behaviour. http://php.net/microtime
	 */
	function microtime_float() {
		list($usec, $sec) = explode(" ", microtime());
		return ((float)$usec + (float)$sec);
	}

	function debug($str) {
		if ($this->debug) {
			echo $str;
		}
	}

}
?>

Last edited by tgbyhn; Sep 7th, 2008 at 10:05 am.

tgbyhn

Reputation Points: 15

Solved Threads: 1

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8 posts
since Sep 2008

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Sep 7th, 2008

Re: check if email address is correct without sending email?

Hi tgbyhn,

Thanks for making those fixes.

Theres a bit of guessing in that class, in the reading from the socket.

The class currently reads from the socket between client and MTA in non-blocking mode.

PHP Syntax (Toggle Plain Text)
socket_set_blocking($this->sock, false);
socket_set_blocking($this->sock, false);

It tries to read from the socket until it receives a few bytes, and will finish reading until that stream is done.

PHP Syntax (Toggle Plain Text)
function send($msg) {
		fwrite($this->sock, $msg."\r\n");
 
		$resp = '';
		$start = $this->microtime_float();
		while(1) {
			$reply = fread($this->sock, 2082);
			$resp .= $reply;
			if (($resp != '' && trim($reply) == '') 
			|| ($this->microtime_float() - $start > $this->max_read_time )) {
				break;
			}
		}
 
		$this->debug(">>>\n$msg\n");
		$this->debug("<<<\n$resp");
 
		return $resp;
	}
function send($msg) {
		fwrite($this->sock, $msg."\r\n");

		$resp = '';
		$start = $this->microtime_float();
		while(1) {
			$reply = fread($this->sock, 2082);
			$resp .= $reply;
			if (($resp != '' && trim($reply) == '') 
			|| ($this->microtime_float() - $start > $this->max_read_time )) {
				break;
			}
		}

		$this->debug(">>>\n$msg\n");
		$this->debug("<<<\n$resp");
		
		return $resp;
	}

The timer:

PHP Syntax (Toggle Plain Text)
$this->microtime_float() - $start > $this->max_read_time )
$this->microtime_float() - $start > $this->max_read_time )

makes sure it doesn't keep reading for ever.

I'd think there is a better way to do this, a more standard way? maybe one defined in the SMTP specs?

Is there a delimiter to wait for when making a read, to know the MTA has finished the response?

At the moment, if the MTA doesn't respond before SMTP_validateEmail::max_read_time then the read will stop, and nothing will be received.

I started with having reads in blocking mode, but with hotmail it hanged on the first read? Maybe it was due to not reading the HELO first, and now that you're updated that reading in blocking mode should work with all MTAs?

edit: Do you think using the "verify" command before trying 'RCPT TO' would be more polite and should give less chance of blacklisting?

Thanks for your time.

Last edited by digital-ether; Sep 7th, 2008 at 11:18 am.

digital-ether

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Reputation Points: 457

Solved Threads: 101

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since Sep 2005

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Sep 7th, 2008

Re: check if email address is correct without sending email?

Hi digital-ether,

Click to Expand / Collapse Quote originally posted by digital-ether ...

Theres a bit of guessing in that class, in the reading from the socket.

The class currently reads from the socket between client and MTA in non-blocking mode.
PHP Syntax (Toggle Plain Text)
socket_set_blocking($this->sock, false);
socket_set_blocking($this->sock, false);
It tries to read from the socket until it receives a few bytes, and will finish reading until that stream is done.
PHP Syntax (Toggle Plain Text)
function send($msg) {
		fwrite($this->sock, $msg."\r\n");
 
		$resp = '';
		$start = $this->microtime_float();
		while(1) {
			$reply = fread($this->sock, 2082);
			$resp .= $reply;
			if (($resp != '' && trim($reply) == '') 
			|| ($this->microtime_float() - $start > $this->max_read_time )) {
				break;
			}
		}
 
		$this->debug(">>>\n$msg\n");
		$this->debug("<<<\n$resp");
 
		return $resp;
	}
function send($msg) { fwrite($this->sock, $msg."\r\n"); $resp = ''; $start = $this->microtime_float(); while(1) { $reply = fread($this->sock, 2082); $resp .= $reply; if (($resp != '' && trim($reply) == '') || ($this->microtime_float() - $start > $this->max_read_time )) { break; } } $this->debug(">>>\n$msg\n"); $this->debug("<<<\n$resp"); return $resp; }
The timer:
PHP Syntax (Toggle Plain Text)
$this->microtime_float() - $start > $this->max_read_time )
$this->microtime_float() - $start > $this->max_read_time )
makes sure it doesn't keep reading for ever.

I've done a few more tweaks, and a bit more testing, I've put it in blocking more (I tried it originally, but forgot about the MTA's greeting so it didn't work). One thing I noticed that using substr isn't really the correct way, as some commands give multiline responses, and I've found out why sometimes there is a hyphen after the response code, the hyphen is used on all the response lines, apart from the last line which should be a space. (see section 3.5.1 in RFC 2821)

Click to Expand / Collapse Quote originally posted by digital-ether ...

I'd think there is a better way to do this, a more standard way? maybe one defined in the SMTP specs?

I've just had a quick read through relevant bits of RFC 2821, I think blocking mode is the way to go, as the MTA should always respond with something. I've put in a socket timeout using PHP's built-in function stream_set_timeout(), so if nothing comes back the script will timeout and return false.

Click to Expand / Collapse Quote originally posted by digital-ether ...

Is there a delimiter to wait for when making a read, to know the MTA has finished the response?

Not afaik, though I could be wrong, and an easy way around it would be to set the buffer to a fairly high figure, so any replies will be read as a whole.

Click to Expand / Collapse Quote originally posted by digital-ether ...

At the moment, if the MTA doesn't respond before SMTP_validateEmail::max_read_time then the read will stop, and nothing will be received.

I started with having reads in blocking mode, but with hotmail it hanged on the first read? Maybe it was due to not reading the HELO first, and now that you're updated that reading in blocking mode should work with all MTAs?

In Hotmail's case it was because of the missing "\r", I know a lot of Windows apps need the "\r" as well as the "\n", whereas Linux/Unix is quite happy with just a "\n". I've just tested the new tweaks on lots of different servers, including Hotmail, Google, Yahoo, and some other, and they all work nicely.

Click to Expand / Collapse Quote originally posted by digital-ether ...

edit: Do you think using the "verify" command before trying 'RCPT TO' would be more polite and should give less chance of blacklisting?

The VRFY command doesn't work in all cases, there's a recommendation in RFC 2821 that it can be a security risk, and that it may be better disabled - VRFY doesn't work for Google, Hotmail or Yahoo. I think the RCPT approach would give a more accurate result.

Adnan

php Syntax (Toggle Plain Text)
<?
/**
 * Validate an Email Address Via SMTP
 * This queries the SMTP server to see if the email address is accepted.
 * @copyright http://creativecommons.org/licenses/by/2.0/ - Please keep this comment intact
 * @author gabe@fijiwebdesign.com
 * @contributers adnan@barakatdesigns.net
 * @version 0.1a
 */
class SMTP_validateEmail {
 
	var $sock;
 
	var $user;
	var $domain;
	var $port = 25;
	var $max_conn_time = 30;
	var $max_read_time = 5;
 
	var $from_user = 'user';
	var $from_domain = 'localhost';
 
	var $debug = false;
 
	function SMTP_validateEmail($email = false, $sender = false) {
		if ($email) {
			$this->setEmail($email);
		}
		if ($sender) {
			$this->setSenderEmail($sender);
		}
	}
 
	function setEmail($email) {
		list($user, $domain) = explode('@', $email);
		$this->user = $user;
		$this->domain = $domain;
	}
 
	function setSenderEmail($email) {
		list($user, $domain) = explode('@', $email);
		$this->from_user = $user;
		$this->from_domain = $domain;
	}
 
	/**
	* Validate an Email Address
	* @param String $email Email to validate (recipient email)
	* @param String $sender Senders Email
	*/
	function validate($email = false, $sender = false) {
		if ($email) {
			$this->setEmail($email);
		}
		if ($sender) {
			$this->setSenderEmail($sender);
		}
		// retrieve SMTP Server via MX query on domain
		$result = getmxrr($this->domain, $hosts, $mxweights);
 
		// retrieve MX priorities
		for($n=0; $n < count($hosts); $n++){
			$mxs[$hosts[$n]] = $mxweights[$n];
		}
 
		asort($mxs);
 
		// last fallback is the original domain
		array_push($mxs, $this->domain);
 
		$this->debug(print_r($mxs, 1));
 
		$timeout = $this->max_conn_time/count($hosts);
 
		// try each host
		while(list($host) = each($mxs)) {
			// connect to SMTP server
			$this->debug("try $host:$this->port\n");
			if ($this->sock = fsockopen($host, $this->port, $errno, $errstr, (float) $timeout)) {
				stream_set_timeout($this->sock, $this->max_read_time);
				break;
			}
		}
 
		// did we get a TCP socket
		if ($this->sock) {
			$reply = fread($this->sock, 2082);
			preg_match('/^([0-9]{3}) /ims', $reply, $matches);
			$code = isset($matches[1]) ? $matches[1] : '';
 
			if($code != '220') {
				// MTA gave an error...
				return false;
			}
 
			// say helo
			$this->send("HELO ".$this->from_domain);
			// tell of sender
			$this->send("MAIL FROM: <".$this->from_user.'@'.$this->from_domain.">");
			// ask of recepient
			$reply = $this->send("RCPT TO: <".$this->user.'@'.$this->domain.">");
			// quit
			$this->send("quit");
			// close socket
			fclose($this->sock);
			// get code and msg from response
			preg_match('/^([0-9]{3}) /ims', $reply, $matches);
			$code = isset($matches[1]) ? $matches[1] : '';
 
			if ($code == '250') {
				// you received 250 so the email address was accepted
				return true;
			} elseif ($code == '451' || $code == '452') {
				// you received 451 so the email address was greylisted (or some temporary error occured on the MTA) - so assume is ok
				return true;
			}
 
		}
 
		return false;
	}
 
 
	function send($msg) {
		fwrite($this->sock, $msg."\r\n");
 
		$reply = fread($this->sock, 2082);
 
		$this->debug(">>>\n$msg\n");
		$this->debug("<<<\n$reply");
 
		return $reply;
	}
 
	/**
	 * Simple function to replicate PHP 5 behaviour. http://php.net/microtime
	 */
	function microtime_float() {
		list($usec, $sec) = explode(" ", microtime());
		return ((float)$usec + (float)$sec);
	}
 
	function debug($str) {
		if ($this->debug) {
			echo $str;
		}
	}
 
}
?>
<?
/**
 * Validate an Email Address Via SMTP
 * This queries the SMTP server to see if the email address is accepted.
 * @copyright http://creativecommons.org/licenses/by/2.0/ - Please keep this comment intact
 * @author gabe@fijiwebdesign.com
 * @contributers adnan@barakatdesigns.net
 * @version 0.1a
 */
class SMTP_validateEmail {

	var $sock;

	var $user;
	var $domain;
	var $port = 25;
	var $max_conn_time = 30;
	var $max_read_time = 5;
	
	var $from_user = 'user';
	var $from_domain = 'localhost';
	
	var $debug = false;

	function SMTP_validateEmail($email = false, $sender = false) {
		if ($email) {
			$this->setEmail($email);
		}
		if ($sender) {
			$this->setSenderEmail($sender);
		}
	}
	
	function setEmail($email) {
		list($user, $domain) = explode('@', $email);
		$this->user = $user;
		$this->domain = $domain;
	}
	
	function setSenderEmail($email) {
		list($user, $domain) = explode('@', $email);
		$this->from_user = $user;
		$this->from_domain = $domain;
	}
	
	/**
	* Validate an Email Address
	* @param String $email Email to validate (recipient email)
	* @param String $sender Senders Email
	*/
	function validate($email = false, $sender = false) {
		if ($email) {
			$this->setEmail($email);
		}
		if ($sender) {
			$this->setSenderEmail($sender);
		}
		// retrieve SMTP Server via MX query on domain
		$result = getmxrr($this->domain, $hosts, $mxweights);

		// retrieve MX priorities
		for($n=0; $n < count($hosts); $n++){
			$mxs[$hosts[$n]] = $mxweights[$n];
		}

		asort($mxs);

		// last fallback is the original domain
		array_push($mxs, $this->domain);
		
		$this->debug(print_r($mxs, 1));
		
		$timeout = $this->max_conn_time/count($hosts);
			
		// try each host
		while(list($host) = each($mxs)) {
			// connect to SMTP server
			$this->debug("try $host:$this->port\n");
			if ($this->sock = fsockopen($host, $this->port, $errno, $errstr, (float) $timeout)) {
				stream_set_timeout($this->sock, $this->max_read_time);
				break;
			}
		}
	
		// did we get a TCP socket
		if ($this->sock) {
			$reply = fread($this->sock, 2082);
			preg_match('/^([0-9]{3}) /ims', $reply, $matches);
			$code = isset($matches[1]) ? $matches[1] : '';

			if($code != '220') {
				// MTA gave an error...
				return false;
			}

			// say helo
			$this->send("HELO ".$this->from_domain);
			// tell of sender
			$this->send("MAIL FROM: <".$this->from_user.'@'.$this->from_domain.">");
			// ask of recepient
			$reply = $this->send("RCPT TO: <".$this->user.'@'.$this->domain.">");
			// quit
			$this->send("quit");
			// close socket
			fclose($this->sock);
			// get code and msg from response
			preg_match('/^([0-9]{3}) /ims', $reply, $matches);
			$code = isset($matches[1]) ? $matches[1] : '';

			if ($code == '250') {
				// you received 250 so the email address was accepted
				return true;
			} elseif ($code == '451' || $code == '452') {
				// you received 451 so the email address was greylisted (or some temporary error occured on the MTA) - so assume is ok
				return true;
			}
		
		}
		
		return false;
	}


	function send($msg) {
		fwrite($this->sock, $msg."\r\n");

		$reply = fread($this->sock, 2082);

		$this->debug(">>>\n$msg\n");
		$this->debug("<<<\n$reply");
		
		return $reply;
	}
	
	/**
	 * Simple function to replicate PHP 5 behaviour. http://php.net/microtime
	 */
	function microtime_float() {
		list($usec, $sec) = explode(" ", microtime());
		return ((float)$usec + (float)$sec);
	}

	function debug($str) {
		if ($this->debug) {
			echo $str;
		}
	}

}
?>

Last edited by tgbyhn; Sep 7th, 2008 at 5:29 pm.

tgbyhn

Reputation Points: 15

Solved Threads: 1

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since Sep 2008

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Sep 7th, 2008

Re: check if email address is correct without sending email?

Beautiful...

digital-ether

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Solved Threads: 101

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1,250 posts
since Sep 2005

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Sep 7th, 2008

Re: check if email address is correct without sending email?

I'm at a net cafe right now so I can't test the class, but a few things after looking at it a bit more:

1) The emails are separated into user and domain portions using explode('@', $email); I remember reading that @ can occur in email username portion if escaped with a backslash, or quoted.

But since domains cannot have @ in them, I think explode() would work by taking the last piece as the domain, and the remaining as the email.

php Syntax (Toggle Plain Text)
function setEmail($email) {
		$parts = explode('@', $email);
		$this->domain = array_pop($parts);
		$this->user= implode('@', $parts);
	}
function setEmail($email) {
		$parts = explode('@', $email);
		$this->domain = array_pop($parts);
		$this->user= implode('@', $parts);
	}

2) The class opens and closes a socket connection to the MTA on each email it validates. Maybe a grouping of emails on the same host could keep the socket alive, and just issue RCPT commands to the open connection? Not even sure if that is supported by SMTP?

I'll see what I can do when I get to a development machine.

digital-ether

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Reputation Points: 457

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since Sep 2005

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Sep 9th, 2008

Re: check if email address is correct without sending email?

Hey Guys,

I've updated the SMTP_validateEmail class with better email address parsing, and it can now validate multiple emails on the same domain via a single socket connection for efficiency.

Also added is support for Windows clients, which requires Net_DNS.
http://pear.php.net/package/Net_DNS

php Syntax (Toggle Plain Text)
<?php
 
 /**
 * Validate Email Addresses Via SMTP
 * This queries the SMTP server to see if the email address is accepted.
 * @copyright http://creativecommons.org/licenses/by/2.0/ - Please keep this comment intact
 * @author gabe@fijiwebdesign.com
 * @contributers adnan@barakatdesigns.net
 * @version 0.1a
 */
class SMTP_validateEmail {
 
 /**
  * PHP Socket resource to remote MTA
  * @var resource $sock 
  */
 var $sock;
 
 /**
  * Current User being validated
  */
 var $user;
 /**
  * Current domain where user is being validated
  */
 var $domain;
 /**
  * List of domains to validate users on
  */
 var $domains;
 /**
  * SMTP Port
  */
 var $port = 25;
 /**
  * Maximum Connection Time to an MTA 
  */
 var $max_conn_time = 30;
 /**
  * Maximum time to read from socket
  */
 var $max_read_time = 5;
 
 /**
  * username of sender
  */
 var $from_user = 'user';
 /**
  * Host Name of sender
  */
 var $from_domain = 'localhost';
 
 /**
  * Nameservers to use when make DNS query for MX entries
  * @var Array $nameservers 
  */
 var $nameservers = array(
	'192.168.0.1'
);
 
 var $debug = false;
 
 /**
  * Initializes the Class
  * @return SMTP_validateEmail Instance
  * @param $email Array[optional] List of Emails to Validate
  * @param $sender String[optional] Email of validator
  */
 function SMTP_validateEmail($emails = false, $sender = false) {
  if ($emails) {
   $this->setEmails($emails);
  }
  if ($sender) {
   $this->setSenderEmail($sender);
  }
 }
 
 function _parseEmail($email) {
 	$parts = explode('@', $email);
	$domain = array_pop($parts);
	$user= implode('@', $parts);
	return array($user, $domain);
 }
 
 /**
  * Set the Emails to validate
  * @param $emails Array List of Emails
  */
 function setEmails($emails) {
 	foreach($emails as $email) {
		list($user, $domain) = $this->_parseEmail($email);
		if (!isset($this->domains[$domain])) {
			 $this->domains[$domain] = array();
		}
		$this->domains[$domain][] = $user;
	}
 }
 
 /**
  * Set the Email of the sender/validator
  * @param $email String
  */
 function setSenderEmail($email) {
	$parts = $this->_parseEmail($email);
	$this->from_user = $parts[0];
	$this->from_domain = $parts[1];
 }
 
 /**
 * Validate Email Addresses
 * @param String $emails Emails to validate (recipient emails)
 * @param String $sender Sender's Email
 * @return Array Associative List of Emails and their validation results
 */
 function validate($emails = false, $sender = false) {
 
  $results = array();
 
  if ($emails) {
   $this->setEmails($emails);
  }
  if ($sender) {
   $this->setSenderEmail($sender);
  }
 
  // query the MTAs on each Domain
  foreach($this->domains as $domain=>$users) {
 
	 $mxs = array();
 
	  // retrieve SMTP Server via MX query on domain
	  list($hosts, $mxweights) = $this->queryMX($domain);
 
	  // retrieve MX priorities
	  for($n=0; $n < count($hosts); $n++){
	   $mxs[$hosts[$n]] = $mxweights[$n];
	  }
	  asort($mxs);
 
	  // last fallback is the original domain
	  array_push($mxs, $this->domain);
 
	  $this->debug(print_r($mxs, 1));
 
	  $timeout = $this->max_conn_time/count($hosts);
 
	  // try each host
	  while(list($host) = each($mxs)) {
	   // connect to SMTP server
	   $this->debug("try $host:$this->port\n");
	   if ($this->sock = fsockopen($host, $this->port, $errno, $errstr, (float) $timeout)) {
	    stream_set_timeout($this->sock, $this->max_read_time);
	    break;
	   }
	  }
 
	  // did we get a TCP socket
	  if ($this->sock) {
	   $reply = fread($this->sock, 2082);
	   $this->debug("<<<\n$reply");
 
	   preg_match('/^([0-9]{3}) /ims', $reply, $matches);
	   $code = isset($matches[1]) ? $matches[1] : '';
 
	   if($code != '220') {
	    // MTA gave an error...
	    foreach($users as $user) {
	    	$results[$user.'@'.$domain] = false;
		}
		continue;
	   }
 
	   // say helo
	   $this->send("HELO ".$this->from_domain);
	   // tell of sender
	   $this->send("MAIL FROM: <".$this->from_user.'@'.$this->from_domain.">");
 
	   // ask for each recepient on this domain
	   foreach($users as $user) {
 
		   // ask of recepient
		   $reply = $this->send("RCPT TO: <".$user.'@'.$domain.">");
 
		    // get code and msg from response
		   preg_match('/^([0-9]{3}) /ims', $reply, $matches);
		   $code = isset($matches[1]) ? $matches[1] : '';
 
		   if ($code == '250') {
		    // you received 250 so the email address was accepted
		    $results[$user.'@'.$domain] = true;
		   } elseif ($code == '451' || $code == '452') {
			// you received 451 so the email address was greylisted (or some temporary error occured on the MTA) - so assume is ok
			$results[$user.'@'.$domain] = true;
		   } else {
		   	$results[$user.'@'.$domain] = false;
		   }
 
	   }
 
	   // quit
	   $this->send("quit");
	   // close socket
	   fclose($this->sock);
 
	  }
 	}
	return $results;
 }
 
 
 function send($msg) {
  fwrite($this->sock, $msg."\r\n");
 
  $reply = fread($this->sock, 2082);
 
  $this->debug(">>>\n$msg\n");
  $this->debug("<<<\n$reply");
 
  return $reply;
 }
 
 /**
  * Query DNS server for MX entries
  * @return 
  */
 function queryMX($domain) {
 	$hosts = array();
	$mxweights = array();
 	if (function_exists('getmxrr')) {
 		getmxrr($domain, $hosts, $mxweights);
 	} else {
 		// windows, we need Net_DNS
		require_once 'Net/DNS.php';
 
		$resolver = new Net_DNS_Resolver();
		$resolver->debug = $this->debug;
		// nameservers to query
		$resolver->nameservers = $this->nameservers;
		$resp = $resolver->query($domain, 'MX');
		if ($resp) {
			foreach($resp->answer as $answer) {
				$hosts[] = $answer->exchange;
				$mxweights[] = $answer->preference;
			}
		}
 
 	}
	return array($hosts, $mxweights);
 }
 
 /**
  * Simple function to replicate PHP 5 behaviour. http://php.net/microtime
  */
 function microtime_float() {
  list($usec, $sec) = explode(" ", microtime());
  return ((float)$usec + (float)$sec);
 }
 
 function debug($str) {
  if ($this->debug) {
   echo htmlentities($str);
  }
 }
 
}
 
 
?>
<?php
 
 /**
 * Validate Email Addresses Via SMTP
 * This queries the SMTP server to see if the email address is accepted.
 * @copyright http://creativecommons.org/licenses/by/2.0/ - Please keep this comment intact
 * @author gabe@fijiwebdesign.com
 * @contributers adnan@barakatdesigns.net
 * @version 0.1a
 */
class SMTP_validateEmail {

 /**
  * PHP Socket resource to remote MTA
  * @var resource $sock 
  */
 var $sock;

 /**
  * Current User being validated
  */
 var $user;
 /**
  * Current domain where user is being validated
  */
 var $domain;
 /**
  * List of domains to validate users on
  */
 var $domains;
 /**
  * SMTP Port
  */
 var $port = 25;
 /**
  * Maximum Connection Time to an MTA 
  */
 var $max_conn_time = 30;
 /**
  * Maximum time to read from socket
  */
 var $max_read_time = 5;
 
 /**
  * username of sender
  */
 var $from_user = 'user';
 /**
  * Host Name of sender
  */
 var $from_domain = 'localhost';
 
 /**
  * Nameservers to use when make DNS query for MX entries
  * @var Array $nameservers 
  */
 var $nameservers = array(
	'192.168.0.1'
);
 
 var $debug = false;

 /**
  * Initializes the Class
  * @return SMTP_validateEmail Instance
  * @param $email Array[optional] List of Emails to Validate
  * @param $sender String[optional] Email of validator
  */
 function SMTP_validateEmail($emails = false, $sender = false) {
  if ($emails) {
   $this->setEmails($emails);
  }
  if ($sender) {
   $this->setSenderEmail($sender);
  }
 }
 
 function _parseEmail($email) {
 	$parts = explode('@', $email);
	$domain = array_pop($parts);
	$user= implode('@', $parts);
	return array($user, $domain);
 }
 
 /**
  * Set the Emails to validate
  * @param $emails Array List of Emails
  */
 function setEmails($emails) {
 	foreach($emails as $email) {
		list($user, $domain) = $this->_parseEmail($email);
		if (!isset($this->domains[$domain])) {
			 $this->domains[$domain] = array();
		}
		$this->domains[$domain][] = $user;
	}
 }
 
 /**
  * Set the Email of the sender/validator
  * @param $email String
  */
 function setSenderEmail($email) {
	$parts = $this->_parseEmail($email);
	$this->from_user = $parts[0];
	$this->from_domain = $parts[1];
 }
 
 /**
 * Validate Email Addresses
 * @param String $emails Emails to validate (recipient emails)
 * @param String $sender Sender's Email
 * @return Array Associative List of Emails and their validation results
 */
 function validate($emails = false, $sender = false) {
 	
  $results = array();

  if ($emails) {
   $this->setEmails($emails);
  }
  if ($sender) {
   $this->setSenderEmail($sender);
  }

  // query the MTAs on each Domain
  foreach($this->domains as $domain=>$users) {
  	
	 $mxs = array();
  
	  // retrieve SMTP Server via MX query on domain
	  list($hosts, $mxweights) = $this->queryMX($domain);

	  // retrieve MX priorities
	  for($n=0; $n < count($hosts); $n++){
	   $mxs[$hosts[$n]] = $mxweights[$n];
	  }
	  asort($mxs);
	
	  // last fallback is the original domain
	  array_push($mxs, $this->domain);
	  
	  $this->debug(print_r($mxs, 1));
	  
	  $timeout = $this->max_conn_time/count($hosts);
	   
	  // try each host
	  while(list($host) = each($mxs)) {
	   // connect to SMTP server
	   $this->debug("try $host:$this->port\n");
	   if ($this->sock = fsockopen($host, $this->port, $errno, $errstr, (float) $timeout)) {
	    stream_set_timeout($this->sock, $this->max_read_time);
	    break;
	   }
	  }
	 
	  // did we get a TCP socket
	  if ($this->sock) {
	   $reply = fread($this->sock, 2082);
	   $this->debug("<<<\n$reply");
	   
	   preg_match('/^([0-9]{3}) /ims', $reply, $matches);
	   $code = isset($matches[1]) ? $matches[1] : '';
	
	   if($code != '220') {
	    // MTA gave an error...
	    foreach($users as $user) {
	    	$results[$user.'@'.$domain] = false;
		}
		continue;
	   }

	   // say helo
	   $this->send("HELO ".$this->from_domain);
	   // tell of sender
	   $this->send("MAIL FROM: <".$this->from_user.'@'.$this->from_domain.">");
	   
	   // ask for each recepient on this domain
	   foreach($users as $user) {
	   
		   // ask of recepient
		   $reply = $this->send("RCPT TO: <".$user.'@'.$domain.">");
		   
		    // get code and msg from response
		   preg_match('/^([0-9]{3}) /ims', $reply, $matches);
		   $code = isset($matches[1]) ? $matches[1] : '';
		
		   if ($code == '250') {
		    // you received 250 so the email address was accepted
		    $results[$user.'@'.$domain] = true;
		   } elseif ($code == '451' || $code == '452') {
			// you received 451 so the email address was greylisted (or some temporary error occured on the MTA) - so assume is ok
			$results[$user.'@'.$domain] = true;
		   } else {
		   	$results[$user.'@'.$domain] = false;
		   }
	   
	   }
	   
	   // quit
	   $this->send("quit");
	   // close socket
	   fclose($this->sock);
	  
	  }
 	}
	return $results;
 }


 function send($msg) {
  fwrite($this->sock, $msg."\r\n");

  $reply = fread($this->sock, 2082);

  $this->debug(">>>\n$msg\n");
  $this->debug("<<<\n$reply");
  
  return $reply;
 }
 
 /**
  * Query DNS server for MX entries
  * @return 
  */
 function queryMX($domain) {
 	$hosts = array();
	$mxweights = array();
 	if (function_exists('getmxrr')) {
 		getmxrr($domain, $hosts, $mxweights);
 	} else {
 		// windows, we need Net_DNS
		require_once 'Net/DNS.php';

		$resolver = new Net_DNS_Resolver();
		$resolver->debug = $this->debug;
		// nameservers to query
		$resolver->nameservers = $this->nameservers;
		$resp = $resolver->query($domain, 'MX');
		if ($resp) {
			foreach($resp->answer as $answer) {
				$hosts[] = $answer->exchange;
				$mxweights[] = $answer->preference;
			}
		}
		
 	}
	return array($hosts, $mxweights);
 }
 
 /**
  * Simple function to replicate PHP 5 behaviour. http://php.net/microtime
  */
 function microtime_float() {
  list($usec, $sec) = explode(" ", microtime());
  return ((float)$usec + (float)$sec);
 }

 function debug($str) {
  if ($this->debug) {
   echo htmlentities($str);
  }
 }

}

 
?>

digital-ether

Moderator

Reputation Points: 457

Solved Threads: 101

Nearly a Posting Virtuoso

Offline

1,250 posts
since Sep 2005

Permalink

Sep 10th, 2008

Re: check if email address is correct without sending email?

Hi digital-ether,

Thanks for your update, however I've just noticed a bug in my last update, line 141 was incorrectly adding an array, which was breaking things if there was no MX record.

PHP Syntax (Toggle Plain Text)
$mxs[$this->domain] = '0';
$mxs[$this->domain] = '0';

Click to Expand / Collapse Quote originally posted by digital-ether ...

Hey Guys,

I've updated the SMTP_validateEmail class with better email address parsing, and it can now validate multiple emails on the same domain via a single socket connection for efficiency.

Also added is support for Windows clients, which requires Net_DNS.
http://pear.php.net/package/Net_DNS

Here is the latest update including your update:

php Syntax (Toggle Plain Text)
<?php
 
 /**
 * Validate Email Addresses Via SMTP
 * This queries the SMTP server to see if the email address is accepted.
 * @copyright http://creativecommons.org/licenses/by/2.0/ - Please keep this comment intact
 * @author gabe@fijiwebdesign.com
 * @contributers adnan@barakatdesigns.net
 * @version 0.1a
 */
class SMTP_validateEmail {
 
 /**
  * PHP Socket resource to remote MTA
  * @var resource $sock 
  */
 var $sock;
 
 /**
  * Current User being validated
  */
 var $user;
 /**
  * Current domain where user is being validated
  */
 var $domain;
 /**
  * List of domains to validate users on
  */
 var $domains;
 /**
  * SMTP Port
  */
 var $port = 25;
 /**
  * Maximum Connection Time to an MTA 
  */
 var $max_conn_time = 30;
 /**
  * Maximum time to read from socket
  */
 var $max_read_time = 5;
 
 /**
  * username of sender
  */
 var $from_user = 'user';
 /**
  * Host Name of sender
  */
 var $from_domain = 'localhost';
 
 /**
  * Nameservers to use when make DNS query for MX entries
  * @var Array $nameservers 
  */
 var $nameservers = array(
	'192.168.0.1'
);
 
 var $debug = false;
 
 /**
  * Initializes the Class
  * @return SMTP_validateEmail Instance
  * @param $email Array[optional] List of Emails to Validate
  * @param $sender String[optional] Email of validator
  */
 function SMTP_validateEmail($emails = false, $sender = false) {
  if ($emails) {
   $this->setEmails($emails);
  }
  if ($sender) {
   $this->setSenderEmail($sender);
  }
 }
 
 function _parseEmail($email) {
 	$parts = explode('@', $email);
	$domain = array_pop($parts);
	$user= implode('@', $parts);
	return array($user, $domain);
 }
 
 /**
  * Set the Emails to validate
  * @param $emails Array List of Emails
  */
 function setEmails($emails) {
 	foreach($emails as $email) {
		list($user, $domain) = $this->_parseEmail($email);
		if (!isset($this->domains[$domain])) {
			 $this->domains[$domain] = array();
		}
		$this->domains[$domain][] = $user;
	}
 }
 
 /**
  * Set the Email of the sender/validator
  * @param $email String
  */
 function setSenderEmail($email) {
	$parts = $this->_parseEmail($email);
	$this->from_user = $parts[0];
	$this->from_domain = $parts[1];
 }
 
 /**
 * Validate Email Addresses
 * @param String $emails Emails to validate (recipient emails)
 * @param String $sender Sender's Email
 * @return Array Associative List of Emails and their validation results
 */
 function validate($emails = false, $sender = false) {
 
  $results = array();
 
  if ($emails) {
   $this->setEmails($emails);
  }
  if ($sender) {
   $this->setSenderEmail($sender);
  }
 
  // query the MTAs on each Domain
  foreach($this->domains as $domain=>$users) {
 
	 $mxs = array();
 
	  // retrieve SMTP Server via MX query on domain
	  list($hosts, $mxweights) = $this->queryMX($domain);
 
	  // retrieve MX priorities
	  for($n=0; $n < count($hosts); $n++){
	   $mxs[$hosts[$n]] = $mxweights[$n];
	  }
	  asort($mxs);
 
	  // last fallback is the original domain
	  $mxs[$this->domain] = '0';
 
	  $this->debug(print_r($mxs, 1));
 
	  $timeout = $this->max_conn_time/count($hosts);
 
	  // try each host
	  while(list($host) = each($mxs)) {
	   // connect to SMTP server
	   $this->debug("try $host:$this->port\n");
	   if ($this->sock = fsockopen($host, $this->port, $errno, $errstr, (float) $timeout)) {
	    stream_set_timeout($this->sock, $this->max_read_time);
	    break;
	   }
	  }
 
	  // did we get a TCP socket
	  if ($this->sock) {
 
	   $reply = fread($this->sock, 2082);
	   $this->debug("<<<\n$reply");
 
	   preg_match('/^([0-9]{3}) /ims', $reply, $matches);
	   $code = isset($matches[1]) ? $matches[1] : '';
 
	   if($code != '220') {
	    // MTA gave an error...
	    foreach($users as $user) {
	    	$results[$user.'@'.$domain] = false;
		}
		continue;
	   }
 
	   // say helo
	   $this->send("HELO ".$this->from_domain);
	   // tell of sender
	   $this->send("MAIL FROM: <".$this->from_user.'@'.$this->from_domain.">");
 
	   // ask for each recepient on this domain
	   foreach($users as $user) {
 
		   // ask of recepient
		   $reply = $this->send("RCPT TO: <".$user.'@'.$domain.">");
 
		    // get code and msg from response
		   preg_match('/^([0-9]{3}) /ims', $reply, $matches);
		   $code = isset($matches[1]) ? $matches[1] : '';
 
		   if ($code == '250') {
		    // you received 250 so the email address was accepted
		    $results[$user.'@'.$domain] = true;
		   } elseif ($code == '451' || $code == '452') {
			// you received 451 so the email address was greylisted (or some temporary error occured on the MTA) - so assume is ok
			$results[$user.'@'.$domain] = true;
		   } else {
		   	$results[$user.'@'.$domain] = false;
		   }
 
	   }
 
	   // quit
	   $this->send("quit");
	   // close socket
	   fclose($this->sock);
 
	  }
 	}
	return $results;
 }
 
 
 function send($msg) {
  fwrite($this->sock, $msg."\r\n");
 
  $reply = fread($this->sock, 2082);
 
  $this->debug(">>>\n$msg\n");
  $this->debug("<<<\n$reply");
 
  return $reply;
 }
 
 /**
  * Query DNS server for MX entries
  * @return 
  */
 function queryMX($domain) {
 	$hosts = array();
	$mxweights = array();
 	if (function_exists('getmxrr')) {
 		getmxrr($domain, $hosts, $mxweights);
 	} else {
 		// windows, we need Net_DNS
		require_once 'Net/DNS.php';
 
		$resolver = new Net_DNS_Resolver();
		$resolver->debug = $this->debug;
		// nameservers to query
		$resolver->nameservers = $this->nameservers;
		$resp = $resolver->query($domain, 'MX');
		if ($resp) {
			foreach($resp->answer as $answer) {
				$hosts[] = $answer->exchange;
				$mxweights[] = $answer->preference;
			}
		}
 
 	}
	return array($hosts, $mxweights);
 }
 
 /**
  * Simple function to replicate PHP 5 behaviour. http://php.net/microtime
  */
 function microtime_float() {
  list($usec, $sec) = explode(" ", microtime());
  return ((float)$usec + (float)$sec);
 }
 
 function debug($str) {
  if ($this->debug) {
   echo htmlentities($str);
  }
 }
 
}
 
 
?>
<?php
 
 /**
 * Validate Email Addresses Via SMTP
 * This queries the SMTP server to see if the email address is accepted.
 * @copyright http://creativecommons.org/licenses/by/2.0/ - Please keep this comment intact
 * @author gabe@fijiwebdesign.com
 * @contributers adnan@barakatdesigns.net
 * @version 0.1a
 */
class SMTP_validateEmail {

 /**
  * PHP Socket resource to remote MTA
  * @var resource $sock 
  */
 var $sock;

 /**
  * Current User being validated
  */
 var $user;
 /**
  * Current domain where user is being validated
  */
 var $domain;
 /**
  * List of domains to validate users on
  */
 var $domains;
 /**
  * SMTP Port
  */
 var $port = 25;
 /**
  * Maximum Connection Time to an MTA 
  */
 var $max_conn_time = 30;
 /**
  * Maximum time to read from socket
  */
 var $max_read_time = 5;
 
 /**
  * username of sender
  */
 var $from_user = 'user';
 /**
  * Host Name of sender
  */
 var $from_domain = 'localhost';
 
 /**
  * Nameservers to use when make DNS query for MX entries
  * @var Array $nameservers 
  */
 var $nameservers = array(
	'192.168.0.1'
);
 
 var $debug = false;

 /**
  * Initializes the Class
  * @return SMTP_validateEmail Instance
  * @param $email Array[optional] List of Emails to Validate
  * @param $sender String[optional] Email of validator
  */
 function SMTP_validateEmail($emails = false, $sender = false) {
  if ($emails) {
   $this->setEmails($emails);
  }
  if ($sender) {
   $this->setSenderEmail($sender);
  }
 }
 
 function _parseEmail($email) {
 	$parts = explode('@', $email);
	$domain = array_pop($parts);
	$user= implode('@', $parts);
	return array($user, $domain);
 }
 
 /**
  * Set the Emails to validate
  * @param $emails Array List of Emails
  */
 function setEmails($emails) {
 	foreach($emails as $email) {
		list($user, $domain) = $this->_parseEmail($email);
		if (!isset($this->domains[$domain])) {
			 $this->domains[$domain] = array();
		}
		$this->domains[$domain][] = $user;
	}
 }
 
 /**
  * Set the Email of the sender/validator
  * @param $email String
  */
 function setSenderEmail($email) {
	$parts = $this->_parseEmail($email);
	$this->from_user = $parts[0];
	$this->from_domain = $parts[1];
 }
 
 /**
 * Validate Email Addresses
 * @param String $emails Emails to validate (recipient emails)
 * @param String $sender Sender's Email
 * @return Array Associative List of Emails and their validation results
 */
 function validate($emails = false, $sender = false) {
 	
  $results = array();

  if ($emails) {
   $this->setEmails($emails);
  }
  if ($sender) {
   $this->setSenderEmail($sender);
  }

  // query the MTAs on each Domain
  foreach($this->domains as $domain=>$users) {
  	
	 $mxs = array();
  
	  // retrieve SMTP Server via MX query on domain
	  list($hosts, $mxweights) = $this->queryMX($domain);

	  // retrieve MX priorities
	  for($n=0; $n < count($hosts); $n++){
	   $mxs[$hosts[$n]] = $mxweights[$n];
	  }
	  asort($mxs);
	
	  // last fallback is the original domain
	  $mxs[$this->domain] = '0';
	  
	  $this->debug(print_r($mxs, 1));
	  
	  $timeout = $this->max_conn_time/count($hosts);
	   
	  // try each host
	  while(list($host) = each($mxs)) {
	   // connect to SMTP server
	   $this->debug("try $host:$this->port\n");
	   if ($this->sock = fsockopen($host, $this->port, $errno, $errstr, (float) $timeout)) {
	    stream_set_timeout($this->sock, $this->max_read_time);
	    break;
	   }
	  }
	 
	  // did we get a TCP socket
	  if ($this->sock) {

	   $reply = fread($this->sock, 2082);
	   $this->debug("<<<\n$reply");
	   
	   preg_match('/^([0-9]{3}) /ims', $reply, $matches);
	   $code = isset($matches[1]) ? $matches[1] : '';
	
	   if($code != '220') {
	    // MTA gave an error...
	    foreach($users as $user) {
	    	$results[$user.'@'.$domain] = false;
		}
		continue;
	   }

	   // say helo
	   $this->send("HELO ".$this->from_domain);
	   // tell of sender
	   $this->send("MAIL FROM: <".$this->from_user.'@'.$this->from_domain.">");
	   
	   // ask for each recepient on this domain
	   foreach($users as $user) {
	   
		   // ask of recepient
		   $reply = $this->send("RCPT TO: <".$user.'@'.$domain.">");
		   
		    // get code and msg from response
		   preg_match('/^([0-9]{3}) /ims', $reply, $matches);
		   $code = isset($matches[1]) ? $matches[1] : '';
		
		   if ($code == '250') {
		    // you received 250 so the email address was accepted
		    $results[$user.'@'.$domain] = true;
		   } elseif ($code == '451' || $code == '452') {
			// you received 451 so the email address was greylisted (or some temporary error occured on the MTA) - so assume is ok
			$results[$user.'@'.$domain] = true;
		   } else {
		   	$results[$user.'@'.$domain] = false;
		   }
	   
	   }
	   
	   // quit
	   $this->send("quit");
	   // close socket
	   fclose($this->sock);
	  
	  }
 	}
	return $results;
 }


 function send($msg) {
  fwrite($this->sock, $msg."\r\n");

  $reply = fread($this->sock, 2082);

  $this->debug(">>>\n$msg\n");
  $this->debug("<<<\n$reply");
  
  return $reply;
 }
 
 /**
  * Query DNS server for MX entries
  * @return 
  */
 function queryMX($domain) {
 	$hosts = array();
	$mxweights = array();
 	if (function_exists('getmxrr')) {
 		getmxrr($domain, $hosts, $mxweights);
 	} else {
 		// windows, we need Net_DNS
		require_once 'Net/DNS.php';

		$resolver = new Net_DNS_Resolver();
		$resolver->debug = $this->debug;
		// nameservers to query
		$resolver->nameservers = $this->nameservers;
		$resp = $resolver->query($domain, 'MX');
		if ($resp) {
			foreach($resp->answer as $answer) {
				$hosts[] = $answer->exchange;
				$mxweights[] = $answer->preference;
			}
		}
		
 	}
	return array($hosts, $mxweights);
 }
 
 /**
  * Simple function to replicate PHP 5 behaviour. http://php.net/microtime
  */
 function microtime_float() {
  list($usec, $sec) = explode(" ", microtime());
  return ((float)$usec + (float)$sec);
 }

 function debug($str) {
  if ($this->debug) {
   echo htmlentities($str);
  }
 }

}

 
?>

Adnan

tgbyhn

Reputation Points: 15

Solved Threads: 1

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8 posts
since Sep 2008

Permalink

Sep 10th, 2008

Re: check if email address is correct without sending email?

Hi Folks, I have done a little on the class SMTP_validateEmail this morning, as it is something I have been meaning to implement for a few months. - nice work so far, thanks.

Basically, I would like to get a confirmed "NO" if the email address is 553, like when Joe Public typoes his address in as jowpublic@domain.com on my site, and a confimed "YES" if I can get at least a postive 25x or 45x from the MX. In all other cases, what I am going to do is remind the user that I was unable to verify the address and ask them to look at it twice for typos before finally hitting submit.

So, as you can see, I have moved away from just returning true/false, to also returning some text strings to check for. This could maybe be done in a better way.

I have also added a nasty hack to work on windoze without NET_DNS, the ability to set nameservers when initialising the class and I have added to, and formatted the debug output a little. There's also a few other little changes in there as you can see.

Thanks again.

K.

Attached Files

code.txt (8.8 KB, 92 views)

Last edited by peter_budo; Sep 10th, 2008 at 3:42 pm. Reason: Posted code moved to attachment at it was breaking Firefox view

whytek

Reputation Points: 10

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