I use Gmail, because my main e-mail accounts are with Gmail. I've tried the Email app for a non-Gmail account before, and it seemed to work fine. I don't know if you can put non-Gmail accounts into the Gmail app, but you ought to be able to put Gmail accounts into the Email app. So I guess if you need/want to access both Gmail and non-Gmail accounts in a single app, Samsung's Email app may be the better choice. If you don't need to do that, or don't mind working with two apps, you can put your Gmail accounts in the Gmail app and other ones in the Email app.