Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.440
diff -u -F^f -r1.440 common.inc
--- includes/common.inc	7 May 2005 01:48:06 -0000	1.440
+++ includes/common.inc	10 May 2005 20:52:52 -0000
@@ -587,12 +587,23 @@ function check_plain($text) {
  *   TRUE if the address is in a valid format.
  */
 function valid_email_address($mail) {
-  $user = '[a-zA-Z0-9_\-\.\+\^!#\$%&*+\/\=\?\`\|\{\}~\']+';
-  $domain = '(?:(?:[a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\-]*[a-zA-Z0-9])\.?)+';
-  $ipv4 = '[0-9]{1,3}(\.[0-9]{1,3}){3}';
-  $ipv6 = '[0-9a-fA-F]{1,4}(\:[0-9a-fA-F]{1,4}){7}';
+  /* We don't support folding whitespace here. */
+  $cfws = "";
+  $atext = "[-a-zA-Z0-9!#$%&'*+\\/=?^_`{|}~]";
+  $atom = "(?:$cfws)?(?:$atext)+(?:$cfws)?";
+  $dot_atom_text = "(?:$atext)+(?:\\.(?:$atext)+)*";
+  $dot_atom = "(?:$cfws)?$dot_atom_text(?:$cfws)?";
+  /* We don't support quoted strings here. */
+  $quoted_string = "";
+  $domain_literal = '\[[^\[\]\\]*\]';
+
+  $local_part = "(?:$dot_atom|$quoted_string)";
+  $domain = "(?:$dot_atom|$domain_literal)";
+
+  $addr_spec = "$local_part@$domain";
+
+  return preg_match("/^$addr_spec\$/", $mail);
 
-  return preg_match("/^$user@($domain|(\[($ipv4|$ipv6)\]))$/", $mail);
 }
 
 /**