POP Access Being Blocked?

POP Access Being Blocked?

First, this morning when I opened Windows Live Mail on my computer, Zoho had downloaded ALL my inbox twice more. 
Second, I just logged in to Zoho mail online and there is a red message across top that says Your POP Access Has Been Blocked, Please Click Here to Unblock....

What is going on? Was my account hacked? Why was my POP blocked and now I am afraid to unblock it as it seems ot be downloading multiple copies of my inbox to my Live Mail on my computer. How can I get help with this?