gistfile1.txt

 $email_params = array(
          'subject' => 'PAPERS User has been merged',
          'body' => 'PAPERS user "' . $other->display_name . '" has updated their username from "' . $other->external_identifier . '" to "' . $main->external_identifier . '".  Please update your records.',
          'from' => '[email protected]',
        );
        drupal_mail('oasis_cas_service_tracking', 'merge_notification', variable_get('oasis_cas_papers_admin_email'), language_default(), $email_params);