@elizarov this comment brings up a good point: https://www.reddit.com/r/programming/comments/5ovu2g/kotlin_11_beta_is_here/dcmq7e4/ Isn't the async in the name of sendEmailAsync(): Future<Email> a repetition since a future is already returned. It seems more something you'd add on a suspending function since with a suspending function you can't figure out from the return type if it suspends or not.