Omar blogged on Boomerang, a technology that we developed at Hotmail to verify that replies to emails you send out from Hotmail make it back to your inbox and not in your Junk folder. I’ll spare you the details since Omar does an excellent job of describing it, but it was a great project to be a part of: it started with Eliot dropping in my office saying he had an idea to knocking it out in the “vNexts” of all our Hotmail components. A simple technology that has a long of bang for the development buck.