mail on my MacMini is only visible in full screen
Mail is only visible in full screen, when i click to take it out of full screen it just shrinks and disappears. It started this one day when I took it out of full screen mode. What do I need to do get it where i can take it in an out of full screen mode and it remain visible?
OSX 10.10.2
Mac mini, OS X Yosemite (10.10.2)