f8lee Loc: New Mexico

Okay, this is taking a long shot, I realize...

So running Ventura with Mail version 16 - been using Macs for many years and so a lot of emails have accrued in the various folders I set up.

There are a number of folders under the "On My Mac" section. When I send photos out to various friends I drag the mailed item from my Sent folder over to the one titled "Photo Stuff" - and over the years it has accumulated a few hundred emails in toto.

So here's the thing - this afternoon I went to that folder and it was epty. Devoid of any content! Mind you, the other dozen or more folders in the On My Mac section are unscathed, and I know for sure I did not do a select-all-delete move on that folder's contents.

So I went into the Library-->Mail subfolder zoo and searched and searched, to no avail. I use Time Machine, but without knowing what sub-sub-sub-sub-and infinitum folder(s) to look for there's no point in going back in time. So I am wondering if a Mac expert has any thoughts...and TIA if you do!

Bret P Loc: California

LOL, Mac ex-expert (mostly retired from IT) I'm on Monterey.
Under the hood, Mail is a mess of uselessly-named nested folders, finding a folder like your Photo Stuff folder can be done.
Finding a certain email or attachment is really difficult.
So restore a whole folder (like Photo Stuff) to your desktop and then import into Mail.

Hmm, seems like you were in the right place:
Hard Drive/Users/Your user name/Library/Mail/V9/C3E3A0BA-652E-4A76-B2ED/Photo Stuff

Your user name is what you sign in to your mac with. Mine is Bret.
V9 is whatever your mail "version" is. If you have more than one "V" folder there, it should be the one with the highest number. Yours is probably V10.

In the V10 (or whatever number) is a "MailData" folder, ignore that one.
One of the other folders will be the folder that has the Photo Stuff folder.
(it's your email account, named obscurly, mine starts with C3E3A0BA-652E-4A76-B2ED) ?

If you have multiple folders in your "V10" folder, they are various email accounts (iCloud, gMail, your ISP etc) that you have synced with your Mail app.

Just click on each folder inside the "V10" folder untill you find the one that matches the folders in "On my Mac" in Mail.
THAT is your email account. (or you may have several if you use several accounts)

I don't really use Time Machine, and apparently importing old emails can be tricky, this might help, but they are talking about restoring a several email accounts entirely, you'll want to just restore a few folders in one (or maybe several) accounts:

https://apple.stackexchange.com/questions/453280/how-to-restore-email-from-a-time-machine-backup

Mark Sturtevant Loc: Grand Blanc, MI

I think there is a point to going back into Time Machine, even if you aren't sure where to start. Start anyway. Go back a month, and pick a random backup. Go back 2 months... Unless you don't think the lost mail is worth it.

f8lee Loc: New Mexico

Well, I do appreciate your attempts to help me, but I have not been able to find the files. I have attached a screenshot of my Mail program's left column - You can see that under the "On my Mac" section there is a folder named Inbox, and within that a number of folders (and subfolders). The thing is, the other folders - Funnies, Friends stuff, etc., have not lost any emails that I have dragged into them over the years. But somehow the Fatelyfoto folder was completely empty - I dragged the four entries you see there now the other day while I was trying to find the other stuff...they were still in the "Sent" folder.

So I went back a couple of months in TimeMachine - went to the V10 file in Mail - found all that gobbldeygook that morons at Apple decided to name things - opened EVERY sub folder but either found stuff that was general mail which was deleted long ago,; no hint of the stuff that was On My Mac...is there a different place where that is stored perchance?

Again, thanks for trying to help - this is one of the things that really annoys me about Apple (and I've been a user since the Mac IIc) - for all the superficial ease of use when it gets to the nuts and bolts it is just nuts, at least IMHO.