Tried all sorts of things, it finally came down to Spam Sieve, had to disable filtering in Mac Mail. Continues to work in Outlook. Naturally I just activated it to get the crash log and atm it is working fine lol . Will monitor and update
With macOS Sonoma, there is no SpamSieve code running in Mail, so any crashes would be due to a bug in Mail or macOS more generally. That said, if Mail is crashing (i.e. macOS is showing a window saying that Mail unexpectedly quit), please send in the crash log file and we’ll take a look.
Two crash reports attached, I suspect you are right, probably correlation, but not causation
Mail Crash.pdf (293 KB)
Mail Crash 2.pdf (270 KB)
Yes, this looks like a bug with Mail’s IMAP syncing. It’s not even currently processing a command from SpamSieve.
Got any suggestions?
It might help to rebuild your Mail database.
Doing a complete rebuild alas, thanks for your help