[sf-lug] Migrated wrong set from thunderbird, lost a bunch of folders. Can I be saved?

[Michael Shiloh]

First of all I confess to being very foolhardy. I always install all 
Ubuntu updates without backing up my system, I use the latest version of 
Ubuntu, Thunderbird, and Firefox, I even run experimental versions with 
wild abandon.

I've been using Thunderbird for some time. Starting somewhere in the 
past month, when starting Thunderbird, I get a message saying I'm using 
a new version, and a migration assistant offers to migrate my settings. 
It gave me three choices: 1) continue to use old settings 2) migrate to 
new settings 3) decide later.

I'm  not even sure which versions this referred to. As I mentioned, I 
was probably using a bleeding edge beta, so it's possible that the 
"upgrade" was just an official install of something I was already using, 
or possibly even a downgrade.

Up until yesterday I chose 3), decide later, because I couldn't be 
bothered to figure out what settings these were, and whether I preferred 
to old or the new.

Yesterday for some reason I chose 2), migrate to new settings.

I didn't notice any difference and forgot about it, until this morning, 
when I noticed that that a whole lot of folders that I had created in 
the past few months were missing, and a big chunk of mail that had been 
sitting in my inbox is gone.

I can't recall when I made these changes to my inbox folders, but the 
missing mail is conveniently timestamped. I'm missing 1/3/2010 - 1/18/2011.

My question is whether I can go back to the previous settings and 
retrieve my mail and folder structure.

Oh, how I miss the old days of mbox format and mutt. I may go back. Of 
course you could fuck yourself over royally back then, and I did, many 
times, but at least I understood clearly what I did. For me the main 
attraction of computers is the learning opportunities.