This is where all the magic happens. Starting up the app for every
arriving message is probably a bad idea. Better – Java server, then
pass it the message.
channel – mailing list
Mailing lists are simpler to track than chat channels. I can work on
the References header (and the attribution if necessary).
onMessage: Extract the References header. Find the latest one and root
the thread there.
I need a registry of message IDs and authors, then.
– What about digest users? Should infer based on attribution as well.