Unable to open mail.
Hi
I have a mac book pro running on El Capitan, running fine until yesterday evening when I opened mail. The icon bounced and the black dot appeared underneath it in the dock. The mail information appears at the top of the page but nothing else. I have tried clicking on new window or bring all to front but nothing happens. I dont have 2 desktops open. Does anyone have any suggestions please as I can't see any recent postings with regard to this subject
Thanks
Anne
MacBook Pro, Mac OS X (10.7.4), 2.4 GHZ INTEL CORE I5