jkt_'s comments

Interesting, because the only slow action when opening mailboxes is fetching and applying the thread index, and gmail does not support that particular feature. Which means I don't really know how it can take a "few minutes" on GMail -- all it does it simply fetching the UIDs...

Nobody builds the Windows binaries regularly. Last time I did so, it worked without any problem. If you'd like to help maintain the Windows port, I'll be happy to have you on board.

Support for GPG is one of the most popular suggestions for this year's GSoC. I cannot promise anything, but it shuold be there "soon".