Future, async, and promises: basic questions



I just found this terrific video from the 2018 RStudio Conference on the upcoming asynchronous possibilities in Shiny.

A couple of questions:

Does Future() actually do what's described in the video if Shiny Server is running on an inexpensive AWS instance with only one core?

I really need this for -- believe it or not -- sending email with the mailR package, which blocks everything else for about 10 seconds. But what happens if the user enters email text, clicks send, and then ends the session before the Future(send.email) has completed? Does ending the session end the Future process, too? Or does the session wait for the Future process to finish and allow somehow dealing with any errors?



Noticing that Joe has been active lately, I'd like to bump this question from a couple a weeks ago back to the top of the queue. - Tom