[Derek_MK]

I mean metaphorically sure, but in this case it's literally using the exact same system; it's just the clients are changed to look like a chat app instead of an email app. This is more like if two people were sending telegraphs over actual telegraph lines, with morse code and everything, then at the end they type it up into a Word document and say "It's email!"

[throwanem]

And? What makes "chat" is synchrony and to a certain extent UI, not transport protocol.

[rafbuff]

Yeah, so why not put everything in one bucket that you control, your mailbox. Part of the idea.