Email validator rewrite (Ticket #6)

Doctrine/Validator/Email.php

 <?php
 class Doctrine_Validator_Email {
     /**
+     * @link http://iamcal.com/publish/articles/php/parsing_email/pdf/
      * @param Doctrine_Record $record
      * @param string $key
      * @param mixed $value
@@ -11,13 +12,35 @@ class Doctrine_Validator_Email {
         if(empty($value)) 
             return true;
 
-        return self::validateEmail($value);
+        $parts = explode("@", $value);
+        if(isset($parts[1]) && function_exists("checkdnsrr")) {
+            if( ! checkdnsrr($parts[1], "MX"))
+                return false;
+        }
+
+        $qtext = '[^\\x0d\\x22\\x5c\\x80-\\xff]';
+        $dtext = '[^\\x0d\\x5b-\\x5d\\x80-\\xff]';
+        $atom = '[^\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]+';
+        $quoted_pair = '\\x5c[\\x00-\\x7f]';
+        $domain_literal = "\\x5b($dtext|$quoted_pair)*\\x5d";
+        $quoted_string = "\\x22($qtext|$quoted_pair)*\\x22";
+        $domain_ref = $atom;
+        $sub_domain = "($domain_ref|$domain_literal)";
+        $word = "($atom|$quoted_string)";
+        $domain = "$sub_domain(\\x2e$sub_domain)*";
+        $local_part = "$word(\\x2e$word)*";
+        $addr_spec = "$local_part\\x40$domain";
+
+        return (bool)preg_match("!^$addr_spec$!", $value);
     }
     /**
      * validateEmail
      *
+     * method not used anymore (should be removed)
+     *
+     * @deprecated
      * @param string $value
-     */
+     *
     public static function validateEmail($value) {
         $parts = explode("@", $value);
 
@@ -54,5 +77,6 @@ class Doctrine_Validator_Email {
 
         return true;
     }
+    */
 }