I want push mail. On my htc 10 this does not cause any better drain. As Steve Jobs said, if the OS requires a task manager, it already failed. I don't want all the time to look what apps are open. The OS should be intelligent enough to handle this for me. Of course I have disabled edge running in the background. Facebook beta is also disabled to run in the background. All these things do not really help. Only battery saver mode helps, but then what is the point of having a smartphone that isn't really that smart?
I understand your point of view (and I have the same), my point is:
- there ar a ton of apps when installed, put themselves as a background app (ex: games, photo apps etc..) and don't make sense to have it there.
- regarding the email: if you really need the email to be received immediately, then ok... you will have a increased drain of the battery. example: I have 3 email accounts... 2 of them are not priority, so the email sync is hourly.. 3 email accounts checking the server all the time is not good.
I assume you have automatic backups enabled, so you can reset the phone (settings, about, reset) and restore from the backup. it takes 30 min.
After all apps are installed again, give it one day or two...you will see the battery will be better.
Also, as another tip, due to the high resolution of the phone (1440x2560) which can have as much as almost 3700million pixels (much more than an iPhone 7 2000million pixels for example), and because it's an OLED screen, you can greatly improve the battery using dark themes.
When black the pixels are not lit and not consuming battery.
Also the OS has a great feature: battery app. You can check which apps are demanding more battery and see if it makes sense or not.
The battery on a moderate use (no games) of internet, emails, some pics, should last a day (12h) on the 950xl 3340MaH battery.
Best of luck.