In fact, I learnt a lot about how #Thunderbird and @mozilla are actually related, and I always thought it's a hardwired #Mozilla product just like #Firefox.
I'm really looking forward to the improvements in Supernova and also future updates to #K9Mail. I used to be a #GMail user but ran into performance problems on older devices and under bad networking conditions. Not a problem for good old #IMAP! :)