The first rule of internet when roaming is make sure that your phone is NOT allowing data to be accessed when roaming. Data charges are still very expensive when roaming but if you contact your network provider before travelling, you may find that they have some cost effective packages that can be enabled during your trip! There is a second option to reduce data usage, some phones support data to be enabled but can turn off all background activity, this means that you can manually go to your email account and tap on Send/Receive or Sync!