Maybe I wasn't clear, my bad.
TMO's international email plan gives free email and I know TMO also charges for data [$15 or $19 per mb ]. I was referring to only emails and not surfing internet [downloading data, checking weather, sports, news, etc].

Also, not familar with android but is there way to pull vs push email? With iPhone, you can configure settings to:
1. fetching emails manually.
2. turning off network

If android has similar functions, then I could wait to download emails until i'm connected to wifi.