How can I disable mail.app?

I want to disable mail.app. I don't buy that it's "needed by OS X." I want it shut off, or preferably uninstalled. I found a better app that still lets me read newsgroups, and mail.app just gets in the way. I had to go in and tell Google Calendar to shut off email notifications to stop the Notification Center from opening mail.app without me wanting it.

I might consider re-enabling mail.app, but not now. Maybe not ever. I bought a Mac so applications would only run when I want them. This is not it.