Haha, I often come here to read @glnz posts, just for that extra comical effect.
I remember that I transferred my OE emails to Thunderbird, but it was a decade or more ago, I don't even remember how I did it, so sorry I can't help with that.
As for the XP after the last patch Tuesday, I intend to use it as long as it is possible, not just because I like it, but for my current hardware is not capable for running something newer, except some Linux distros, which I use from time to time.
And I have no doubt, this great XP loving community at MSFN, and some others will still be alive and kicking, for years to come.