How to turn off duplicate email notification messages? Recently bought a Samsung Galaxy 2.

There's a built-in app for both Gmail and general e-mail. I've been using the general e-mail app.

I'm finding that I'm getting notifications from both apps for the same new Gmail e-mail that comes in.  Is there a way to turn off the Gmail app notifications?  (I tried deleting the app outright but it seems Samsung won't let me do this. It's not an option in the manage applications menu, whereas it is for other 3rd party apps.)
In the settings of the gmail app there is a setting called "Email notifications".  Uncheck that setting, and you should stop getting notifications from it.