Janie- Click on "Settings" to the right in the status box under your username.
Once there click on "Email".
Once there go to the bottom of the page and check the box that states, "I don't want to receive emails from Navy for Moms".
Click "Save" to save your changes.
If you still receive some from the groups you are on you may need to "stop following" them. Try the settings thing first.
Hope that helps.