We are researching different approaches to run a background task in Android and iOS. We have heard client-side tasks can be very battery intensive. Since our app involves polling an imap server, why not compare to a similar service.
We were wondering, which approach does Gmail/Outlook use? Does it poll and check email on the client device using a background task, then send a local notification? Or does it poll and check on its servers and send a remote notification via its GCM push notification service to the client?