Mail App Error

I use the mail application connected to my comcast.net e-mail address on my macbook pro to manage my mail. A few days ago the comcast mail server was down, so I obviously was unable to retrieve my email on the web or via the mail application. Now, the server is back up, I can check it online, but whenever the mail application tries to retrieve email, it says there is an error, and that the port is timed out. What do I do? Thanks in advance.

 

i dont have an iphone. im on a macbook pro