Index: invite.module
===================================================================
--- invite.module        (revision 379)
+++ invite.module        (working copy)
@@ -1013,7 +1013,7 @@
 function _invite_get_emails($string) {
   $valid_emails = $failed_emails = array();
   $user = '[a-zA-Z0-9_\-\.\+\^!#\$%&*+\/\=\?\`\|\{\}~\']+';
-  $domain = '(?:(?:[a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\-]*[a-zA-Z0-9])\.?)+';
+  $domain = '(?:(?:(?:[a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)+[a-zA-Z0-9]{2,6})';
   $ipv4 = '[0-9]{1,3}(\.[0-9]{1,3}){3}';
   $ipv6 = '[0-9a-fA-F]{1,4}(\:[0-9a-fA-F]{1,4}){7}';
   $rx = "/($user@($domain|(\[($ipv4|$ipv6)\])))>?$/";