Mail essentially unusable following upgrade to Catalina

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:

Re-install Catalina
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!!

Try deleting your gmail and Exchange accounts and re-establishing them. That has worked for most, but not all users.

Already did this….three times…

Did Apple change anything on their server side filtering or a change in the iOS 13 Mail filtering with update? I have not upgraded to Catalina but the filtering of my emails is moving many into the Junk folder that would have been in the Inbox. And when I went to move a message I was reading to Not Junk, it only gave me the option to a Move To Junk. So it did not think it was in the Junk folder. Is there some kind of indexing problem so that when people went to empty their Junk mail, it deleted more? It was thinking that my Junk Folder items were not tagged as Junk.

Is that part of this Mail problem?

The only unusual thing I’ve noticed in Mail after upgrading to Catalina is that sometimes the account listing order gets suddenly switched and I have to switch it back. Otherwise things seem basically the same to me. I have 6 account: 3 are Gmail, one is iCloud and two are generic IMAP accounts. No Exchange accounts.

I’ve had that happen in all recent MacOS releases.

Why not give Postbox a try? It has the ease of use and simplicity of Apple Mail, but with more power and features. We have a free 30-day trial, so you have nothing to lose.

Full disclosure: We are Postbox!

I actually have a license and have started to setup Postbox for my email. I need to import rules and saved email and then should be good to go.

This is really strange. Since I upgraded my Mail has been working great. I have several accounts, including one gmail and hundreds of mailboxes. Just one thought, are you by any chance running a VPN? When I was running ExpressVPN there were huge issues and had to setup protocols to get the VPN to ignore Apple Mail.

Are your mailboxes “On My Mac”? Have you confirmed that all the contents of the messages are intact?

All are fully functioning and I am missing nothing. I must admit I do most of my email via iCloud addresses but I am having no problems with any others. In fact it has been behaving so well that I stopped using both Spark and Airmail 3.

No VPN in use

Got hit with that one as well

I’m baffled then because like I have said I am having no problems at all. Really wish I could help!