We are experiencing a significant number of links in our emails being altered by email firewalls resulting in recipients experiencing peculiar unsubscribe form behavior that is troublesome. For example, one firewall product replaces any email address in our unsubscribe URLs with email@example.com.
Has anyone explored an alternative method for unsubscribe links that works well? We are considering using cid and checksum, but the form won't work once the token expires. We are using CiviCRM 5.21.3 on Drupal 7.73. Thanks for any suggestions you may have.