I absolutely can't stand Full Screen mode. Never, ever use it and don't want to. This is not about that "full screen".

I have always made my mail client window full screen size by either double-clicking the title bar, or since I use BetterTouchTool, just dragging it to the top of the screen and it instantly goes full size. Simple.

Today, this doesn't work any more. The mail window will never go full screen, only to some pre-determined maximum size that leaves considerable space at the sides and bottom. No amount of dragging will go larger, and double-click on the title bar maxes out at this new, sub-full-screen size.

Works normally in all other apps, double-click title bar and they take up the entire window.

What gives here? This is a new behavior, just started this morning. Anyone have any idea why this is happening and how to stop it? macOS Catalina.

EDIT: Today, it's not doing this any more. I have no idea why. I had even rebooted yesterday morning and it was still doing it. But not today. Very strange!

  • Double-click the bottom right corner, when you see the double arrow. See apple.stackexchange.com/questions/423256/… for some of the vagaries of how this works.
    – Tetsujin
    Commented Feb 15, 2022 at 22:04
  • Nope, not a single thing in that answer works for me, at all, in any way. None of what it describes is true for me.
    – JVC
    Commented Feb 15, 2022 at 22:07
  • This problem has now disappeared, I have no idea why.
    – JVC
    Commented Feb 16, 2022 at 11:43


You must log in to answer this question.

Browse other questions tagged .