Slow or no response to mouse-click

If it does let me get to my email, I have to wait 30 seconds for each mouse-click to respond.  Even then, it will often return to a previous page, scroll down the page, or simply do nothing.  I can't check emails to be deleted.  I can't open others.  As a matter of fact, I couldn't even close this session!  That's why I'm writing this sentence!