E-mail validering

Jeg har efterhånden tit siddet og bladret rundt på nettet for at finde et ordentligt script til at validere e-mails med. Og eftersom jeg af mystiske årsager aldrig kan finde det script jeg fandt sidst jeg ledte, så er det efterhånden blevet til et par gange 😛

Nu vil jeg så gå så langt som til at sige at jeg har fundet den “perfekte” function til at validere e-mails.

 

Funktionen gør følgende:

• Tjekker om e-mailen har gyldigt e-mail syntaks
• Laver MX-record tjek på den host der er angivet i e-mailen
• Forsøger at sende en mail fra e-mailen, til e-mailen

 

Jeg har herunder tilladt mig at vise kildekoden til en redigeret (forkortet) udgave af funktionen som er skrevet af Mark “Tarquin” Wilton-Jones.

/**
 * Email address validation script
 * v2.1.1 Written by Mark 'Tarquin' Wilton-Jones - 26-28/01/2004
 * Updated 12/02/2004 to allow all valid email address formats and
 * improve RFC compliance, and use MX record weightings
 * Updated 09/05/2004 to allow Norwegian characters
 */
function checkEmail($email, $debug = false){
	$msgs = Array();
	$msgs[] = 'Received email address: '.$email;
	if (!preg_match("/^(([^<>()[].,;:s@"]+(.[^<>()[].,;:s@"]+)*)|("([^"r]|([wW]))*"))@(([([0-9]{1,3}.){3}[0-9]{1,3}])|(([a-z-0-9áàäçéèêñóòôöüæøå]+.)+[a-z]{2,}))$/i", $email)){
		$msgs[] = 'Email address was not recognised as a valid email pattern';
		return $debug ? array(false, $msgs) : false;
	}
	$msgs[] = 'Email address was recognised as a valid email pattern';
	if (preg_match("/@[[d.]*]$/", $email)){
		$mxHost[0] = preg_replace("/[wW]*@[([d.]+)]$/", "$1", $email);
		$msgs[] = 'Email address contained IP address '.$mxHost[0].' - no need for MX lookup';
	}
	else{
		$domain = preg_replace("/^[wW]*@([^@]*)$/i", "$1", $email);
		if (!getmxrr($domain, $mxHost, $weightings)){
			$mxHost[0] = $domain;
			$msgs[] = 'Failed to obtain MX records, defaulting to '.$domain.' as specified by SMTP protocol';
		}
		else{
			array_multisort($weightings, $mxHost);
			$cnt = '';
			$co = 0;
			foreach ($mxHost as $ch){
				$cnt.= ($cnt ? ', ' : '').$ch.' ('.$weightings[$co].')';
				$co++;
			}
			$msgs[] = 'Obtained the following MX records for '.$domain.': '.$cnt;
		}
	}
	foreach ($mxHost as $currentHost){
		$msgs[] = 'Checking MX server: '.$currentHost;
		if ($connection = fsockopen($currentHost, 25, $error_int, $error_str, 5)){
			$msgs[] = 'Created socket ('.$connection.') to '.$currentHost;
			if (preg_match( "/^2dd/", $cn = fgets($connection, 1024))){
				$msgs[] = $currentHost.' sent SMTP connection header - no futher MX servers will be checked: '.$cn;
				while (preg_match("/^2dd-/", $cn)){
					$cn = fgets($connection, 1024);
					$msgs[] = $currentHost.' sent extra connection header: '.$cn;
				}
				if (!$_SERVER){
					global $HTTP_SERVER_VARS;
					$_SERVER = $HTTP_SERVER_VARS;
				}
				$localHostIP = gethostbyname(preg_replace("/^.*@|:.*$/", '', $_SERVER['HTTP_HOST']));
				$localHostName = gethostbyaddr($localHostIP);
				fputs($connection, 'HELO '.($localHostName?$localHostName:('['.$localHostIP.']'))."rn");
				if ($success = preg_match( "/^2dd/", $hl = fgets($connection, 1024))){
					$msgs[] = $currentHost.' sent HELO response: '.$hl;
					fputs($connection, "MAIL FROM: <$email>rn");
					if ($success = preg_match( "/^2dd/", $from = fgets($connection, 1024))){
						$msgs[] = $currentHost.' sent MAIL FROM response: '.$from;
						fputs($connection, "RCPT TO: <$email>rn");
						if ($success = preg_match("/^2dd/", $to = fgets($connection, 1024))){
							$msgs[] = $currentHost.' sent RCPT TO response: '.$to;
						}
						else{
							$msgs[] = $currentHost.' rejected recipient: '.$to;
						}
					}
					else{
						$msgs[] = $currentHost.' rejected MAIL FROM: '.$from;
					}
				}
				else{
					$msgs[] = $currentHost.' rejected HELO: '.$hl;
				}
				fputs($connection, "QUITrn");
				fgets($connection, 1024);
				fclose($connection);
				$msgs[] = $success ? ('Email address was accepted by '.$currentHost) : ('Email address was rejected by '.$currentHost);
				return $debug ? array($success, $msgs) : $success;
			}
			elseif (preg_match("/^550/", $cn)){
				$msgs[] = 'Mail domain denies connections from this host - no futher MX servers will be checked: '.$cn;
				return $debug ? array(false, $msgs) : false;
			}
			else{
				$msgs[] = $currentHost.' did not send SMTP connection header: '.$cn;
			}
		}
		else{
			$msgs[] = 'Failed to create socket to '.$currentHost;
		}
	}
	$msgs[] = 'Could not establish SMTP session with any MX servers';
	return $debug ? array(false, $msgs) : false;
}}