I still rely on e-mail for most interactions despite my interest in bots and messaging, so I'm especially intrigued by e-mail bots. X.ai is one of a handful of bots that can be invoked by cc'ing an e-mail address; the bot takes over and handles the usual back-and-forth of picking a convenient time to meet. It'll be interesting to see social conventions develop around these bots. There's a strong signal in cc'ing an assistant to schedule a meeting (you generally do it for people whom you outrank in some respect) and that signal is arguably even stronger when you cc a bot. That said, maybe everyone will eventually have a scheduling bot and we'll become used to adding them in all the time.