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

Hi, I was going through the list of emails given to test this validation function and when I entered abc\\@example.com the third email address down on the list of emails that should not be valid, it said it was valid and sent the email.

Is there something wrong? should this email address validate? Is there an error in the list of emails that should not pass validation?

just wondering :o/

If you have added some non dns based TLD (top level Domain) checking - beware! It is highly probable that in the near future TLD's will be opened up and could get quite long.

email addresses like: myname@thisisareallylongtld could be valid, and under the spec they are legal (note the lack of .'s).

Assuming that all tld's will be 6 chars or less, just because that is presently true is short sighted. I have seen people use email checkers with an internal list of TLD's to compare to, and they have been frustrated out how out of date such lists become.

Email addresses like;
me@a
me@a.b.c
me@jhsdfjhasdlfjkhasdfiuyerkjbhsdjkfasdjfbalskdjfhasdfasdfasdfasdf
me@lh-lkj.lkj-lkj
me@a-b-c-d-e-f-g

Could potentially be used in the future - While DNS may be expensive, if you want to be certain that the domain is valid, DNS is the only way this can be achieved.

Your code doesn't seem to disallow consecutive hyphens in the domain name, which it should (unless internationalized, in why case the domain address may begin: xn--).

The following regex, I believe, complies completely with RFC 5322. And also does away with the need for any further functions (save for checking to see if the domain name actually exists):

/^(?=.{5,254})(?:(?:\"[^\"]{1,62}\")|(?:(?!\.)(?!.*\.[.@-])[a-z0-9!#$%&'*+\/=?^_`{|}~^.-]{1,64}))@(?:(?:\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9]?[0-9])\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9]?[0-9])\])|(?:(?!-)(?!.*-\$)(?!.*-\.)(?!.*[^n]--)(?!.*[^x]n--)(?!n--)(?!.*[^.]xn--)(?:[a-z0-9-]{1,63}\.){1,127}(?:[a-z0-9-]{1,63})))$/i

I added another else if to the test because i noticed that bob@yahoo would pass. So I added a check to see if there is a dot 4 positions before the end of the domain section. View below:

else if(substr($domain,($domainLen - 4),1) != ".")
{
//no dot 4 positions before the end
$isValid = false;
}

What do you think about filter_var function? It's standart php function for validate data.
You can see example in my blog - Email validation without regexp.

In Russian Проверка Email на php.

First off,
DNS lookups are quite slow, but without them this script will validate many obviously wrong addresses (like "a@b").

With a google search, I found this function which is much faster and it does a pretty good job, especially for not relying on the DNS at all...

function emailcheck($email) {
		return preg_match('/^(?:[\w\!\#\$\%\&\'\*\+\-\/\=\?\^\`\{\|\}\~]+\.)*[\w\!\#\$\%\&\'\*\+\-\/\=\?\^\`\{\|\}\~]+@(?:(?:(?:[a-zA-Z0-9_](?:[a-zA-Z0-9_\-](?!\.)){0,61}[a-zA-Z0-9_]?\.)+[a-zA-Z0-9_](?:[a-zA-Z0-9_\-](?!$)){0,61}[a-zA-Z0-9_]?)|(?:\[(?:(?:[01]?\d{1,2}|2[0-4]\d|25[0-5])\.){3}(?:[01]?\d{1,2}|2[0-4]\d|25[0-5])\]))$/', $email);
}

Also,
instead of:
preg_match('/\\.\\./', $local)

use:
strpos($local,'..')!==false)

strpos() is much faster than preg_match.

Great script with comments and explanations so you can learn and understand what the code is doing!! Excellent!!

These validations will reject 'postmaster' which is, at least in some circumstances such as an SMTP RCPT line, required to be considered a valid email address.

I wrote my own e-mail validation function after spending hours with RFC 2822. It passes all of the above test cases with NOYB's corrections. I would appreciate if you submit any bugs to: geoffreyj.lee at Gmail.

function validateEmail($input)
{
  $atom = '[a-zA-Z0-9!#$%&\'*+\-\/=?^_`{|}~]+';
  $quoted_string = '"[^"\\\\\r\n]*"';
  $word = "$atom(\.$atom)*";
  $domain = "$atom(\.$atom)+";
  return strlen($input) < 256
    && preg_match("/^($word|$quoted_string)@{$domain}\$/", $input);
}

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 ?