Security: How to obtain someone’s username/login from the “Gmail for work”?

Photo: freeimages.com Short version: Gmail leaks your username. Always! To get username/login information for Google Apps user (paid Work/Business account) you need one email message. Just look at the Return-Path header. Fortunately, you do not know password yet, but combined with other weaknesses (like password reuse) this is not a problem. Determining if someone is …