By default, all contributions add the associated email address to our mailing list. In the case of people who are either already subscribed, or who are logged in to a Drupal account (which also are default opted in to the mailing list), upon completing the contribution, they receive a CiviCRM info message stating " is already subscribed to the list."
Obviously we'd like to avoid this if possible. Is there a way to avoid trying to subscribe people to the list if they are already added?