Richard Groff2 wrote:
This Mail message icon occasionally pops up in my dock. When I click it it takes me to Mail and shows a message window with "Loading..." forever.
I have a new Mac mini M4 running Sequoia 15.5. Here's what it looks like:
https://discussions.apple.com/content/attachment/df184639-76be-44ca-a5f5-d1552e969b7f
Old issue, new issue, what changed?
Try launching the Mail.app from the Applications folder and compare your results(?)
Quit the Mail.app and relaunch it holding the Shift key down and compare your results.
Did you try logging into your mail through a browser(?) this would tell you if you have your password correct and the server is up and running.
There are further instructions here if necessary delete the account and add it back i:
If you can’t send or receive email on Mac - Apple Support
Note—
IMAP accounts stay on the server, so no local loss, when you re-sync
POP accounts download and remove from the server—therefor save your inbox/sent box if you want them
“On My Mac" is just that, local folders you created and moved mail into. So no loss
A Safeboot a can sort issue Start up your Mac in safe mode - Apple Support
Login and test. Reboot as normal and test. Caches get rebuilt automatically.