Long, sad story. I may have lost 25 years' worth of Thunderbird email folders - spanning most of my medical/academic career, plus personal communications (including exchanges with friends now dearly-departed), my medical records, purchase/guarantee receipts, ticket purchases, amazon, etc etc. I tried to activate the free Nomorobo on Optimum/Cablevision unsuccessfully, and in a series of tech support calls, following their directions (in retrospect eggregiously wrong), I was told to change my thunderbird password, then delete and reactivate my thunderbird account. When I did that, all my previous folders (about 150 folders) stored on my computer disappeared. This is a major data repository for the last 25 years of my life. Now, I can receive and send messages (after another several hours of "support") but my old records are gone. Can they be restored, maybe with File History? or are there any other potential things I could try. They were not backed up anywhere else, so far as I can tell. I'm not even sure where the current (almost empty inbox, sent and trash) folders are kept.