Google Gmail uses a to step verification. When you try to read emails on your laptop Gmail will send a request to your phone saying a new device is trying to connect to Gmail. You must answer the question on your phone telling that is you trying to connect using a new device. Gmail will then let your laptop read and have access to your Gmail account. This stops people who don't have your phone from reading your emails because on another device. They can't answer the question with out your phone to tell Gmail it is you trying to connect with a new device. I think this is the same with all email systems. So leave your phone on when you connect with a new device so you can tell Gmail it is you trying to connect. It's a pain in the rear end. Hope this works for you because I had the same problem. Bye Neil D.