Mail: cannot reply to messages.
iMac 21 inch late 2012. OS X El Capitan.
Mail: Since yesterday I can't reply to messages. First the reply button didn't work. Then I used the right click to reply but now that doesn't work either. An empty mail window appears but I can't do anything with it, not even close it.
Any suggestions? Thnx!
iMac (21.5-inch, Late 2012), OS X El Capitan (10.11.2)