<?php
function emailvalidate( $email ) {
$isValid = true;
$atIndex = strrpos($email, "@");
if (is_bool($atIndex) && !$atIndex) {
$isValid = false;
}
else {
$domain = substr($email, $atIndex+1);
$local = substr($email, 0, $atIndex);
$localLen = strlen($local);
$domainLen = strlen($domain);
if ($localLen < 1 || $localLen > 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 (preg_match('/\\.\\./', $local)) {
// local part has two consecutive dots
$isValid = false;
}
else if (!preg_match('/^[A-Za-z0-9\\-\\.]+$/', $domain)) {
// character not valid in domain part
$isValid = false;
}
else if (preg_match('/\\.\\./', $domain)) {
// domain part has two consecutive dots
$isValid = false;
}
else if ( !preg_match('/^(\\\\.|[A-Za-z0-9!#%&`_=\\/$\'*+?^{}|~.-])+$/',
str_replace("\\\\","",$local))
) {
// char not valid in local part unless local part is quoted
if (!preg_match('/^"(\\\\"|[^"])+"$/', str_replace("\\\\", "", $local))) {
$isValid = false;
}
}
if( $isValid && !(checkdnsrr($domain,"MX") || checkdnsrr($domain, "A"))) {
// domain not found in DNS
$isValid = false;
}
}
return $isValid;
}
?>
Last updated 11 Dec 2012
