If you did not delete the old profile, it may still be there. New installations of TB do not delete existing profiles. Look in the appdata/roaming/thunderbird/profiles and it may be there. If so, it can be reconstructed. But first, verify if it's there.

David thanks for the reply, I did not reinstall TB just set up a new account. Under roaming i currently have XXXXXXX.default which shows created 8/2/2018 (2.86MB) and xxxxxxx.old created 1/27/22 (986MB). i had renamed it.

Good. First, I suggest you copy the 'good' profile and store it where you know it well and rename folder to something easy, such as C:\\MYPROFILE. That is, it does not need to stay in the appdata area. (That step is optional, and is what I do personally.) Next, right click on desktop short cut and add -p to target line so it appears as "c:\\programfiles\thunderbird\thunderbird.exe" -p and close shortcut. Then start TB and a panel will open for profile. Click 'create profile' and browse and select wherever the desired profile is (either the 'good' one in Appdata/roaming or wherever you moved it to. Continue to TB and it will start with the old profile. Once all is okay, remove the -p from shortcut.

Did that work? Let me know. Thanks.

Thanks David, I can at least get back into email now. I have to set up a new account each time and use a password generated at aol yesterday. Also not sure it matters what I use on my end. Also babysitting so may be able to try more later.

AOL now requires an APP password. I think if you log into your AOL account and get to the Security section, there is a place to generate an APP password. Good luck. I respect that babysitting has its priority.

Hi David, No matter what profile I load when i connect with the AOL server it brings back the same 130 or so recent inbox messages plus new ones. My address book is gone too. My sent messages seem to be still on AOL and i moved them to a saved mail area over there. I tried opening TB offline too. When I drill down on one of the bigger profiles in the Mail folder (2.86gb) I see three pop.verizon.net folders, the first has an inbox with 736000 kb, and a sent with 1,499,000 kb, so it seems I still have data. I saw a help answer 1372645 which looks involved, not sure where to go at this point. I checked Archive too and it was set to archive at pop.verizon.net, not locally. I have treated this email rather cavalierly but with the verizon and AOL changes it sure seems to be teetering.

Well, you might try tools>account settings>server and browse the local folder to see which of those three verizon folders works. I admit that I do NOT know POP, having always worked with IMAP, but this may help.

Hi David, Some progress! I have my address book back under collected addresses, personal has a few too. Also, from roaming/default profile/mail I have pop.verizon.net and pop.verizon-1.net and pop.verizon-2.net. From pop.verizon.net I moved inbox and sent to roaming/default profile/Local. This brought back a Local folder upon TB restart which has much of the email archive. My question is how to move the other (mbox files?) mail and sent folders from pop.verizon-1.net and pop.verizon-2.net? or should they have been moved as pop.verizon.net, pop.verizon-1.net, and pop.verizon-2.net?

Okay, I am NOT good with POP. So step carefully here. I suggest you browse in File Explorer those folders to see which has the most current dates in it. My approach would be to test each, with pop.verizon-2.net probably the most recent. It may have everything. You might want to browse contents of a mail folder (such as inbox or sent) with a text editor (such as the freeware edxor.exe - my favorite for browsing irregularly formatted content) to see what messages are there. My guess, and it's just a guess, is that pop.verizon-2.net is the current one. But you will know soon enough. On your question, how to merge them, I don't know. Let me know if you locate the preferred one and we can deal with the others then.

Hi David, here is where I am. I copied pop, pop1 and pop2 inbox files to an outside folder, renamed them and put them in the Local folder. I go back in to TB and access the folders, pop has the most messages and i can see back to 2017. However, then TB deletes 4000 odd messages and I have only more recent years. I thought it was the automatic compacting that may have been doing this and i read https://support.mozilla.org/en-US/questions/1330595 which discusses auto deletion of deleted messages. In any case i turned off compaction, recopied the files and thought i had it when the deletions happened again. i did download exdor and got a look at some of the data but the files were too large. TB itself is the best place to look at them. Some other file/setting must be must be causing the skinnying.

Check your account settings. You may have it set to auto delete old emails. Check tools>account settings>synchronization & storage

Thanks David, I marked this solved, I had not been in that Disk Space section and turning off that switch fixed it! Now I go back to 2017, and now that i know how, I could probably load even older emails if needed. I am also backing up appdata now, thanks again.

I'm pleased you were able to salvage this.