I can't send/receive Hotmail on my iMac. My username and password are correct. What do I do next?

I had this problem on my phone as well but that's fixed. Not even sure how I fixed it; I think I did an account recovery at Hotmal and had to change my password. Now it's popped up on my iMac. I'm sure it's a Hotmail problem and I should just drop my Hotmail account. I have tried using the Connection Doctor in the Mail app and it said to check that my username and password were correct. They are. So I'm at a loss as to what to do next. Any suggestions? Thanks.