It should work very well for specifying the logic around the calendar example: Switchboard would accept the credentials of the accounts to monitor, e.g. calendar@mydomain.com, and then notify a "schedule notification" worker of new messages. The burden of scheduling reminders for participants would be on the worker, but there are a lot of tools for that. I like the idea!

One note: Switchboard is especially useful relative to a bare IMAP connection when you're monitoring many accounts. This is because it provides a lot of the boilerplate around restarting failed connections and issuing IMAP commands while an IMAP connection has an active IDLE continuation.

I agree that there's tons of room for more automation around emails. I think the lack of automation is due to not having high-level tools, which is where Switchboard comes in, and that emails are typically natural language. I'm personally excited to see Switchboard get used for email classification -- imagine if your business-logic could include the email "class", e.g. "sent by a human", or "marketing", ... etc. A bit like Gmail's categories, but open and accessible to developers.