Yesterday I noticed my iPhone 6 Plus going through incredible battery drain. Today I pegged it at about 1% per minute. I took a 1 hour nap yesterday and it dropped a whopping 25%. In settings > usage > battery usage, Mail background tasks takes the cake at 40% in the past 24 hours and a similar story for the last 7 days. A few days ago I wasn't receiving any messages which was odd. I rebooted my iPhone and that fixed it. But I'm not so,some who does a lot of emailing from my iPhone, I check maybe 10 messages a day. This seems really abnormal to me. How can I fix this?