You might want to look at a 3rd party mail app for this. Having it fetch email headers is one thing, but then getting the attachments kinda changes the picture. If you're trying to limit the data use, why would you want attachments?
Another way around it if you are really trying to limit your data use is to create a separate email account. Call this your "notification" account. You don't use it for anything other than the email account you check for notifications of emails from your primary account. Then, on your primary account, just have it send you a notification that you have an email and that's it.