Outlook Online's Delayed Send

I just noticed an interesting possible feature of Microsoft Outlook Online that could save somebody some embarrassment. I say "possible" because the following behavior could conceivably be a product of my sometimes-slow Internet connection, but might also be intentional behavior.

I needed to send a short reply to an e-mail, so I typed it up, checked it, and hit Send. Rather than sending the e-mail immediately, Outlook stamped the message with "[Draft]" and produced a Cancel button off to the right. After a few seconds, the unsent-message instrumentation disappeared and my reply was sent.

I can definitely see that feature being helpful if I had clicked the Send button accidentally. Outlook probably looked at the message's length (short) and the time spent composing it (also short) to guess how confident I was about sending it. I was confident that I wanted it sent in that state, but the delay was worthwhile and not onerous.