Quickest, best answer is to change your profile to "Phone Only" after hours. You can turn the data off on the 8830, but then you can't access the web or use any data features at all. Phone Only will just stop alerting you to emails. When you wake up in the morning, all of the emails will be there.
No, however you can create your own custom profiles. I have one called Phone/Text Only. You just customize the notification settings so that you are only alerted to a call or text. It's really pretty easy if you just go into the Profiles area and hit the menu key to see what options you're given. I don't have my BB in front of me, but I believe when you hit menu it gives you the option to "customize."