I am on a 200 MB/month plan, and feel that Mail is responsible for most of my mobile data usage, sometimes pushing me over the 200 MB, even if I almost never use the iPhone in places where there is no WiFi. I can either setup the phone:
- To use push or pull at a regular interval. In either case, it will sometimes download new mail in the background, while the phone is locked. And this means it will do so over 3G instead of WiFi, even if there is WiFi where I am.
- To disable push and and set fetch to "manually". I guess this will reduce my mobile data usage, but I would then have to wait after launching Mail for it to download my mail.
Ideally, I'd like the iPhone to use "push" when over WiFi and "fetch manually" when over 3G, but there doesn't seem to be an option for this.
What would you say is the optimal setup to reduce the use of mobile data, without going to "fetch manually"?