Hey Frank Lowney1,
Thanks for updating us with that information.
Are you aware if this started around the time any new installs or downloads occurred on your Mac? If you can think of any new downloads or installs that occurred when you first started to notice this, would you be able to remove them temporarily to test?
If you're unsure if any installations around the time this occurred, try setting up a test user account to see if iCloud Mail works better there. For assistance with setting up a test user account, check out this resource and the steps below will get you started: Set up users, guests, and groups on Mac - Apple Support
1. On your Mac, choose Apple menu
> System Preferences, then click Users & Groups
.
If the lock at the bottom left is locked
, click it to unlock the preference pane.
If you see that this isn't occurring with a test user account, this is related to preferences or installations on your primary account.
We hope that's able to help with getting started on isolating what could be causing this.
Have a great day!