Despite people always complaining about their perceived inefficiencies, standard protocols like IMAP or XMPP always seem to work on a crappy connection, when most of the modern web doesn't.
Back in the day when I worked at a WISP with 2.4Ghz mountain top antennas the one thing that would work when we were having massive icing issues was email. It was very impressive how it would get through even with massive packet loss and transfer rates measuring in bytes per second.
Is this a joke? Both XMPP and IMAP are terrible over an unreliable connection.