

Undo Send works by implementing a delay before OWA transmits an outbound message to the server.

Like its Gmail counterpart, OWA’s Undo Send allows you to wait for up to 30 seconds to make your mind up that a message should really go. Undo Send finally made its appearance for Office 365 users in early January 2017. In fact, Undo Send had been available since 2009 as a Google Labs add-in and it was curious why Google took quite so long to give their imprimatur to Undo Send. Well, Microsoft took even longer to decide to introduce an equivalent feature into OWA. In June 2015, Google made the “Undo Send” feature an official part of Gmail.
