Validate an E-Mail Address with PHP, the Right Way

DNS checking is resource intensive. If you take out the DNS checks, all of the bugs in the logic start to appear.

This routine will accept the following as a valid email address:

a@b.c
a@b
a@b.

It is doing zero validation of the host and domain extension. Instead it relies on DNS to do these checks, which is a waste of system resources.

Since this article was posted over two years ago and no corrections have been made, I would suggest looking for something better.

sorry this code have a bug

just test : michael.good@gmail

wihout any .COM or .ANYTHING , the function recognize the email as valid !!!

Thanks mate, this is working just perfectly for me ;-)

Thinks don't have to be perfect in my oppinion, as long as some scumbag spambots cannot spam with viagra_pills@for.free i'm happy :-D

Hi there,
I am using this code to validate emails on the fly with the help of AJAX, on my site. I noticed that as I entered random email addresses the user could simply put
"myemail@a"
and it would consider it valid.
it didn't need the .____ attached.
so I added this to the middle of the validation:

else if (!preg_match('/\\./', $domain))
{
// domain has no dots
$isValid = false;
}

It fixed it.

Thanks for the code :)

Hello guys

i have connection internet and i installed xampp last version i would like to test validation of email this is the form :

Enter your email :

but its not working plz can u help me

replay urgent

This should check the top-level domain as well. I thought everything is fine until someone typed email address like this xxx@yyy.p instead of xxx@yyy.pl . DNS checking is switched off on a server so I cannot validate email address using it.

Lets add:


elseif (strlen(substr($domain, strrpos($domain, '.')+1)) < 2 || strlen(substr($domain, strrpos($domain, '.')+1)) > 6) {
$isValid = false;
}


Top level domain AFAIK is at least 2 char long and 'museum' is longest at the moment. This should do the trick.

Thanks for this code BTW! Very useful.

Great article! Everything was neatly explained. I would say that Tom Burt is right though, the wording in the rule section seems to imply that a domain name can not begin with a number, which of course is wrong.

But what about if I wanted to do it in other languages like ASP.NET, or just plain javascript, is there any chance you will be working on examples for that too? :)

Hello!

First, I want to thank and congratulate the author of this article for its quality and desirability.

I admit that, wishing to write a form that tests the submited addresses, I have been searching for a long time in vain on the Web a document that clearly explains the email addresses syntax, and that it seems I found it here.

I want to write a mail addresses validator that can tell back the visitor the exact nature of the anomaly. Furthermore, I don't want to use regular expressions, often reading bad things about them, and... not knowing how to use them.

So I show you candidly the code I wrote, for submission to the fire of your critics. It is not perfect: particularly in the management of the escapement.

Here you have:

<?php // testor_email_0.php

$testable_mail = html_entity_decode( $mail ) ;
$butee = strlen( $testable_mail ) ;
$aro_pos = strrpos( $testable_mail, $aro ) ;

$nout = array( "nom d'utilisateur", "user name" ) ;
$nodo = array( "nom de domaine", "domain name" ) ;
$car = array( "caractère", "character" ) ;
$et = "être" ;

if( ! $testable_mail )
$avertissement = array( "$viv $adel[$lang_index]", "$svps[$lang_index] include your $adel[$lang_index]" ) ;

else if ( $aro_pos === FALSE )
$avertissement = array( "Votre $adel[$lang_index] doit comporter une arobase", "Your $adel[$lang_index] must include the at sign" ) ;

else if ( $aro_pos == 0 )
$avertissement = array( "Votre $adel[$lang_index] doit comporter un $nout[$lang_index]", "Your $adel[$lang_index] must have a $nout[$lang_index]" ) ;

else if ( $aro_pos == $butee - 1 )
$avertissement = array( "Votre $adel[$lang_index] doit comporter un $nodo[$lang_index]", "Your $adel[$lang_index] must have a $nodo[$lang_index]" ) ;

else if( $testable_mail{0} == $dot )
$avertissement = array( "Un point ne peut pas débuter votre $adel[$lang_index]", "A dot cannot begin your $adel[$lang_index]" ) ;

else if( $testable_mail{$butee - 1} == $dot )
$avertissement = array( "Un point ne peut pas terminer votre $adel[$lang_index]", "A dot cannot end your $adel[$lang_index]" ) ;

else
{
$segments = explode( $dot, $testable_mail ) ;
foreach( $segments as $segment )
if( ! strlen( $segment ) )
{
$avertissement = array( "Deux points ne peuvent pas $et contigus dans votre $adel[$lang_index]", "Two dots can not be contiguous in your $adel[$lang_index]" ) ;
break ;
}

include_once "Data/hilite.php" ;
$numeri_cars = range( "0", "9" ) ;

if( ! $avertissement  ) include "testor_email_1.php" ;
if( ! $avertissement ) include "testor_email_2.php" ;
}

if( $avertissement ) $a_servir = "mail" ;

?>

<?php // testor_email_1.php

$testable_str = substr( $testable_mail, 0,  $aro_pos ) ;
$butee = strlen( $testable_str ) ;

$gui = '"' ;
$gui_nombre = substr_count( $testable_str, $gui ) ;
$dir = dir_extraire( __file__ ) ;

/* longueur maximum */

$max = 64 ;
if( $butee > $max )
$avertissement = array( "Le nombre de car[$lang_index]s de votre $nout[$lang_index] ne peut excéder $max", "The number of car[$lang_index]s in your $nout[$lang_index] can not exceed $max" ) ;


/* point a la fin  */

else if( $testable_str{ $butee - 1 } == $dot )
$avertissement = array( "Un point ne peut $et contigu à l'arobase", "A dot cannot be contiguous to the at sign" ) ;


/* guillemets */

else if( $gui_nombre )
include "$dir/testor_email_guillemets.php" ;


/* defaut */

else
{
$zauts_str = "!, #, $, %, &, ', *, +, -, /, =, ?, ^, _, `, {, |, }, ~, $dot" ;
$zauts_list = explode( $vs, $zauts_str ) ;
$valides = array_merge( $lettres, $numeri_cars, $zauts_list ) ;

for( $i = 0; $i < $butee; $i++ )
{
$ze_car = $testable_str{$i} ;
if( ! in_array( $ze_car, $valides ) )
{
$ze_car = hilite( $ze_car ) ;
$avertissement = array( "Le $car[$lang_index] $ze_car ne peut pas figurer dans votre $nout[$lang_index]", "The $car[$lang_index] $ze_car cannot appear in your $nout[$lang_index]" ) ;
break ;
}
}
}

?>

<?php // testor_email_guillemets.php

if( $gui_nombre == 1 )
$avertissement = array( "Les guillemets doivent  se présenter par paire dans votre $nout[$lang_index]", "The double-quotes must show by pair in your $nout[$lang_index]" ) ;

else if( $gui_nombre == 2 )
{
if( $testable_str{0} != $gui || $testable_str{ $butee - 1 } != $gui ) 
$avertissement = array( "Les guillemets doivent se présenter aux extrémités de votre $nout[$lang_index]", "The double-quotes must show at the ends of your $nout[$lang_index]" ) ;
}

else
$avertissement = array( "Votre $nout[$lang_index] ne peut pas avoir de guillemets ailleurs qu'aux deux extrémités", "Your $nout[$lang_index] cannot have double-quotes anywhere else but at both ends" ) ;

?>

<?php // testor_email_2.php

$testable_str = substr( $testable_mail, $aro_pos + 1 ) ;
$butee = strlen( $testable_str ) ;

$max = 255 ;
if( $butee > $max )
$avertissement = array( "Le nombre de $car[$lang_index]s de votre $nodo[$lang_index] ne peut excéder $max", "The number of $car[$lang_index]s in your $nodo[$lang_index] can not exceed $max" ) ;

else if( $testable_str{0} == $dot )
$avertissement = array( "Le premier $car[$lang_index] de votre $nodo[$lang_index] ne peut pas $et un point", "Your $nodo[$lang_index] can not begin with a dot" ) ;

else
{
$segments = explode( $dot, $testable_str ) ;
foreach( $segments as $segment )
{

$segment_len = strlen( $segment ) ;
$max = 63 ;
if( $segment_len > $max )
{
$avertissement = array( "Le nombre de $car[$lang_index]s entre deux points dans votre $nodo[$lang_index] ne peut excéder $max", "The number of $car[$lang_index]s between two dots in your $nodo[$lang_index] can not exceed $max" ) ;
break ;
}

$ze_car = $segment{0} ;
if( ! in_array( $ze_car, $lettres ) )
{
$ze_car = hilite( $ze_car ) ;
$avertissement = array( "Le $car[$lang_index] $ze_car ne peut pas figurer immédiatement après un point ou l'arobase dans le $nodo[$lang_index] de votre $adel[$lang_index]", "The $car[$lang_index] $ze_car cannot show just after a dot or the at sign in the $nodo[$lang_index] of your $adel[$lang_index]" ) ;
break ;
}

$valides = array_merge( $lettres, $numeri_cars ) ;
$ze_car = $segment{$segment_len-1} ;
if( ! in_array( $ze_car, $valides ) )
{
$ze_car = hilite( $ze_car ) ;
$avertissement = array( "Le $car[$lang_index] $ze_car ne peut figurer : ni immédiatement avant un point dans le, ni à la fin du, $nodo[$lang_index] de votre $adel[$lang_index]",  "The $car[$lang_index] $ze_car cannot show, neither just before a dot in, nor at the end of, the $nodo[$lang_index] of your $adel[$lang_index]" ) ;
break ;
}

$valides[] = $tiret ;
$butee = $segment_len - 1 ;
for( $i = 1; $i < $butee; $i++ )
{
$ze_car = $segment{$i} ;
if( ! in_array( $ze_car, $valides ) )
{
$ze_car = hilite( $ze_car ) ;
$avertissement = array( "Le $car[$lang_index] $ze_car ne peut pas figurer dans votre $nodo[$lang_index]", "The $car[$lang_index] $ze_car cannot appear in your $nodo[$lang_index]" ) ;
break 2 ;
}
}

}
}

if( ! $avertissement )
{
$dot_pos = strrpos( $testable_str, $dot ) ;
if( $dot_pos === FALSE )
$avertissement = array( "Veuillez indiquer un domaine de niveau supérieur à votre $adel[$lang_index]", "$svps[$lang_index] indicate a top level domain to your $adel[$lang_index]" ) ;

if( ! $avertissement )
{
$tld = substr( $testable_str, $dot_pos + 1 ) ;
include "../Data/tlds.php" ;
if( ! in_array( $tld, $tlds ) )
$avertissement = array( "Le domaine de niveau supérieur que vous avez indiqué ne figure pas dans notre liste de référence", "The top level domain you indicate is not in our list" ) ;

if( ! $avertissement && ! checkdnsrr( $testable_str ) && ! checkdnsrr( $testable_str, "A" ) )
$avertissement = array( "Le $nodo[$lang_index] que vous avez indiqué n'est pas reconnu par internet", "The $nodo[$lang_index] you indicate is not recognized by internet" ) ;

}
}

?>

Thank you for your contribution,

Sacapuss

I've had a go at this too. One reason being that the code here is All Rights Reserved by Linux Journal, so I don't think you can use it in your project.

Here's my effort: RFC-compliant email address validator

I've done more checking of the domain part, particularly allowing the IP address format even though it's discouraged by the RFCs.

I believe my function respects RFCs 1123, 2396, 3696, 4291, 4343, 5321 & 5322. Please let me know if you find any problems with it.

<?php
# Offers methods for validating user input

class Validate
{
	static function email($email)
	{
		$isValid = true;
		$atIndex = strrpos($email, '@');

		if (is_bool($atIndex) && !$atIndex)
		{
			return false;
		}
		else
		{
			$domain = substr($email, $atIndex + 1);
			$local = substr($email, 0, $atIndex);
			$validLocalLength = Validate::length($local, 1, 64);
			$validDomainLength = Validate::length($domain, 1, 255);
			$validStartFinish = !($local[0] == '.' || $local[$localLen - 1] == '.');
			$validLocalDots = !preg_match('/\\.\\./', $local);
			$validDomainCharacters = preg_match('/^[A-Za-z0-9\\-\\.]+$/', $domain);
			$validDomainDots = !preg_match('/\\.\\./', $domain);
			$validLocalCharacters = !(!preg_match('/^(\\\\.|[A-Za-z0-9!#%&`_=\\/$\'*+?^{}|~.-])+$/', str_replace("\\\\","",$local)) && !preg_match('/^"(\\\\"|[^"])+"$/', str_replace("\\\\","",$local)));
			$validMailRecord = checkdnsrr($domain, 'MX') || checkdnsrr($domain, 'A');

			return $validLocalLength && $validDomainLength && $validStartFinish && $validLocalDots && $validDomainCharacters && $validDomainDots && $validLocalCharacters && $validMailRecord;
		}
	}

	static function length($input, $min, $max)
	{
		return isset($input[$min - 1]) && !isset($input[$max]);
	}
}
?>

Hei Yo

I used the functionality given in this article in a test case, and emails with quotation marks, with both embedded and without (the embedded ones had proper escape characters) both failed the verification standards...either there must be an update...or someone is lying

bump.

But seriously is this gonna get an update for the problem whereas the domain part of an email adress is not allowed to start with a number and yet the function allows it?

I suppose a simple
filter_var($email, FILTER_VALIDATE_EMAIL);
isn't enough ?

This is very nice routine once for all. Currently i m doing testing on window machine and windows doesnt support checkdnsrr function so i modify it following way to work with Window.

      /* Following code should be activated if hosting is on linux.
      if ($isValid && !(checkdnsrr($domain,"MX") || checkdnsrr($domain,"A")))
      {  // domain not found in DNS
         $isValid = false;
      }
      Following code should be activated if hosting is on windows. */
      if ($isValid && !(myCheckDNSRR($domain,"MX") || myCheckDNSRR($domain,"A")))
      {  // domain not found in DNS
         $isValid = false;

function myCheckDNSRR($hostName, $recType = '')
{
 if(!empty($hostName)) {
   if( $recType == '' ) $recType = "MX";
   exec("nslookup -type=$recType $hostName", $result);
   // check each line to find the one that starts with the host
   // name. If it exists then the function succeeded.
   foreach ($result as $line) {
     if(eregi("^$hostName",$line)) {
       return true;
     }
   }
   // otherwise there was no mail handler for the domain
   return false;
 }
 return false;
}

And please pardon my knowledge, I am very new in programming and just trying to play with it, its not my code i found from other places. But I thought it will help.

Thanks

//NOTE: use this line code :
//                       strEmail= fixBackSlash(strEmail); 
//      only if email address come from a textbox (form);

function isValidEmail(strEmail)
{
	this.strrpos=function( haystack, needle, offset){
		// http://kevin.vanzonneveld.net
		// +   original by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
		// *     example 1: strrpos('Kevin van Zonneveld', 'e');
		// *     returns 1: 16
	 
		var i = haystack.lastIndexOf( needle, offset ); // returns -1
		return i >= 0 ? i : false;
	}

	this.fixBackSlash=function(strEmail)
	{
		var strEmailTemp="";
		var isBackSlash = false;
		for(var j=0;j 64)
		{
			 // local part length exceeded
			 isValid = false;
		}
		else if (domainLen < 1 || domainLen > 255)
		{
			// domain part length exceeded
			isValid = false;
		}
		else if (local[0] == '.' || local[localLen-1] == '.')
		{
			// local part starts or ends with '.'
			isValid = false;
		}
		else if (local.match('\\.\\.'))
		{
			 // local part has two consecutive dots
			 isValid = false;
		}
		else if (!domain.match('^[A-Za-z0-9\\-\\.]+$')|| domain[domainLen-1] == '.')
		{
			// character not valid in domain part
			isValid = false;
		}
		else if (domain.match('\\.\\.'))
		{
			// domain part has two consecutive dots
			isValid = false;
		}
		else if(!localsave.match('^(\\\\.|[A-Za-z0-9!#%&`_=\\/$\'*+?^{}|~.-])+$'))
		{
			// character not valid in local part unless 
			// local part is quoted
			if (!localsave.match('^"(\\\\"|[^"])+"$'))
			{
				isValid = false;
			}
		}
	}
	 return isValid;
}

thank you my page used..