Synchronization between Apple Mail app and Swisscom Mail
After the forced change to Bluewin Email Basic, the synchronization between Bluewin Mail and the Apple Mail apps (desktop and mobile) no longer works adequately. Emails that were read or deleted in the mobile app are still unchanged in both the desktop mail app and the browser version. If email is no longer included in the expensive Swisscom subscription and is billed separately, it should at least work.
Before you get there, mail accounts outside of Bluewin continue to work without any problems. So it’s not a general problem.