Recover missing IMAP emails from Time Machine
I use Apple Mail on my iMac and have 4 email accounts. All are IMAP. A few days ago I was clearing out my inbox / moved almost everything to the trash folder. It was thousands of emails. I opened the trash folder and permanently deleted everything that was over a year old. I'm searching for emails I know are fairly recent and discover one of the email accounts has a year of history as I intended and the other 3 accounts are showing only 2 months. I view all of the accounts aggregated in one Inbox, one trash folder, etc and I didn't inadvertently delete the missing emails but I need them back.
From searches here is what I have tried:
Open Finder/Go to folder: ~/Library/Mail/V10
Click Time Machine icon in Menu Bar/Browse Time Machine Backups
Scroll through backup logs until I reach the desired backup date
Restore/Copy V10 folder to Desktop
Open Mail/Click File/Import Mailboxes/Import Data from Apple Mail/Select V10 file from desktop/Import
The mail folders then all show up under On My Mac/Import BUT the folders are all a carbon copy of my current mail folders. The missing emails I need are still missing. I've tried 3 times with 3 different backup dates I know precede my maintenance on the email folders. I'm doing something wrong. Or lost IMAP emails are not backed up in Time Machine and unrecoverable?
iMac 27″, macOS 13.4