We have changed our email server for specific domain, and added mail settings in groupware. All domains are working fine with auto email setup, but that specific domain still catch settings of old email server. Thus authentication fails.
Please advice procedure remove old email server settings that was manually set before for each user. It seems like mail app cache old email server settings for this specific domain and avoiding groupware settings.
For example, on this email server we have two domains example1.com and example2.com are perfectly working with groupware settings. Now example3.com has been added to this email server, this example3.com was configure in mailapp manually previously with old email server. when user configure email@example.com in auto email setup it picks old email server not groupware settings. For other domains its working fine.