After the upgrade to Catalina, mail has become essentially unusable (2013 Mac Pro). Symptoms include extremely slow switching among different mailboxes. Extremely slow opening of emails and loading of same. 9 different email accounts, 2 exchange and the rest gmail. One of the things that i noticed is that both accountsd and mail have VERY high CPU usage, both hovering above 300%. Occasionally, it will also slow down the entire Mac.
What I have done to try to fix:
Deleted all email accounts and recreated.
Deleted Mail preferences / accounts preferences / related preferences
Disabled contacts syncing
Disabled calendar syncing
Reboot in safe mode
Created new user
Nothing has fixed the issue. Mail usually ends up crashing inside of 24 hours. accountsd crashes about 50% of the time
It does appear to involve accountsd, Apple Mail, Gmail and Exchange/Office365. When all gmail and exchange accounts are disabled, and only iCloud account is enabled, there isn’t an issue.
The same thing happened in the early Catalina Betas on my 2017 Mac Book Pro, but seemed fixed in the mid beta cycle.
Any ideas would be great!!