I rebooted into Safe Boot, tested Mail there and it worked. Restarted normally, and Mail then worked and has been OK since.
aholowka
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution
Last seen
User for
Post
Replies
Boosts
Views
Activity
Not seeing it in my Outlook here.
I have O365 version 16.40 (fast insider) installed.