Connections to host p63-imap.mail.me.com on the default ports failed - red dot in Mail accounts
After working for years, my iCloud E-mail account all of a sudden can no longer connect in Apple Mail (red dot in Accounts list in preferences). The connection doctor log reveals that the Apple Mail client tries to connect to the iCloud IMAP server on port 0 (should be 993). Manually configuring an IMAP client for iCloud in Apple Mail works. It looks like the automatically generated server configuration for iCloud is screwed up. Where is information on IMAP servers including the port number stored? One could probably fix the port number there in some configuration file. I could not find it in the library (checked Prefs, Mail and Containers).
MacBook Air