You know, some app HAS to be at the top of the list and, since it seems that you don't do much with your phone other than GMail, maybe that's why it is way up there.
I know this would be hard to do (it would for me, anyway) but try charging your phone fully and then go 24 hours (okay, maybe 12) without actually opening the GMail app. If the battery use is still high, then it is related to background tasks such as syncing. If the battery use is lower, then the bulk of it may be foreground tasks such as reading mail.
Since you mentioned IMAP, exactly what type and how many different accounts are you tracking with the GMail app? If only a gmail.com address, then that doesn't, so far as I know, use IMAP at all. But if you are syncing IMAP accounts (such as, I think, yahoo.com accounts) too often, then that may certainly be your problem.
12-29-2015 01:28 PM