Apple Core Rot extends to all areas of macOS.
Here, Apple Mail (at least one hour, and attempts after trial) happen. There was no problem with the mail server (on the local LAN, I run my own and I looked at the activity in real time and the logs) – just a bug in Apple Mail.
I started and restarted, turned off different accounts, etc. Finally, it was just beyond what error it ran into.
It's annoying that only Apple Mail decides to go haywire like this.
OWC ThunderBlade sent in the travel case
Charles C writes:
I have switched to Postbox. No more "recovered messages" folder (I had over a thousand ̵2; Apple never explained what they were). I've had it in 3 weeks. Performs very nicely, with some great extras Apple Mail does not have. As a place to store canned responses to emails that you can easily add.
MPG: Worth Watching. An important feature for me is POP support along with a "abandoned mail on server" feature so I can travel and make quick mail on a laptop without losing the ability to download it to my main Mac.