It's funny, I read all through that with my rose tinted glasses thinking they'd created a local IMAP server on the phone, which would have been clever (and, I think, doable)... in fact I was running this perception until "Our proxy server is written in Ruby using EventMachine, which allows it to efficiently handle many concurrent IMAP connections"

And I thought, why the heck would one phone be issuing so many concurrent IMAP connections. Oh my naiveté.