How do I transfer all my comcast emails and contacts to my icloud email?

I have consistant trouble with macmail being able to receive my comcast emails ever since I upgraded my computer to yosemite (many many problems have come from doing that, actually). I spend hours trying to reconfigure my mail, ports, servers, etc. and I am getting tired of it. How can I just have everything exported to my icloud email? I plan to get off comcast anyway and will need to do this. Any help with this and general help about how to fix mail on Yosemite would be appreciated. I'm so angry at my computer after this upgrade I have briefly considered switching to a PC! (kidding)