Recently I've been having troubles with Mail. It keeps downloading the same messages even after they've been deleted. If I delete, then close mail they come in again.
Also it seems to always say "downloading messages" at the bottom left of the screen. I've also noticed its giving the Macbook Pro a hell of a work out. When mail is open the fans go loud, and the battery drains very quickly.
So far I've tried clicking rebuild, no luck. Enabling and disabling the account, no luck. It does give the occasional error message which I click send to Apple. Next time it does it I will post it up.
Macbook Pro Early 2011,
OSX EL Captain 10.11.3
Any help or suggestions would be greatly appreciated. Please understand my knowledge of Mac stuff is pretty limited :)