Monterey Mail app crashes repeatedly, M1 Max and Intel iMac Pro

Does the same issue present while booting in to Safe Mode ?

You don't leave it in Safe Mode. The act of booting into save mode does the following;

NOTE: Safe Mode boot can take up to 3 - 5 minutes as it's doing the following; 

• Verifies your startup disk and attempts to repair directory issues, if needed

• Loads only required kernel extensions (prevents 3rd party kernel/extensions from loading)

• Prevents Startup Items and Login Items from opening automatically

• Disables user-installed fonts 

• Deletes font caches, kernel cache, and other system cache files

So just boot into safe mode and reboot normally. Then see if the problem persists or not.

I also have had this issue since upgrading to Monterey on my 2019 16in MacBook Pro a couple of weeks ago. If I leave Mail open, it is a certainty that the app will crash with the exact same error report as OP provided, except the abort cause is different.

Application Specific Information:
BUG IN CLIENT OF LIBPLATFORM: Trying to recursively lock an os_unfair_lock
Abort Cause 320123

Inevitably, I do leave the Mail app open as a course of habit--and as such, I experience ten or more crashes per day depending on how much I'm using my laptop.

I have not booted into Safe Mode yet. That said: if Mail doesn't crash repeatedly in Safe Mode, I guess that is good--except I still won't know what's causing the repeated crashes, correct?

OP: have you had any success in identifying the root cause of the crashes?

Sam issue here. It will attempt to start downloading emails, then stop, then pinwheel. I have deleted my accounts and re-added them to the app to no avail.

This is one of the most fundamental apps on the platform. I wold think that they would have this issue resolved ASAP, but it is January and the post was over a month ago.

rockrimmon wrote:

I am the OP. I have not booted into safe mode, these are production machines, I can’t boot into safe mode and leave the machine sitting for hours waiting to see if the problem occurs in safe mode.

I finally gave up and installed a third party mail app that has not crashed once.

The purpose of Safe Mode here is to help diagnose the issue as Safe Mode disables non-Apple extensions that are installed. Since this issue is not seen with the vast majority of Mac users, Safe Mode can help determine if something is installed that conflicts.

Do all users experience the issue, or is it just one user?

You can also download and run Etrecheck and post the output here using the Additional Text button below (looks like a sheet of paper with one corner folded). The best results are obtained by granting Etrecheck full access to the computer. It anonymizes the output so no personal info is shown.

I am no fan of Spark mail, but that's what I've resorted to, since my Apple Mail program freezes or crashes CONSTANTLY with Monterey. (Pinwheel of death! Pinwheel of death!!)

Right? I mean, it's one thing if people are having a hard time adjusting their hair colour on a Memoji. But this is MAIL for Pete's sake. C'mon Cupertinos. Get it together!

Yes, still unable to run mail in safe mood after installing Monterey twice.