Index: ucreate.module
===================================================================
--- ucreate.module	(revision 44)
+++ ucreate.module	(working copy)
@@ -190,6 +190,9 @@
     $name = user_access('access user profiles') ? l($account->name, 'user/'. $account->uid) : $account->name;
     form_set_error('name', t('User !name already exists.', array('!name' => $name)));
   }
+  if(!valid_email_address($form_state['values']['mail'])){
+    form_set_error('email_confirm', t('E-mail addresses is invalid!'));
+  }
   if ($form_state['values']['mail'] != $form_state['values']['mail_confirm']) {
     form_set_error('email_confirm', t('E-mail addresses don\'t match'));
   }