My email account was deleted after I had Apple move all of my data from my old Macbook Pro to my new one. How do I get it back?

Yosemite 10.10.5

12" Macbook Pro brand new

I had Apple migrate all of my data from my old Macbook Pro to my new one...one of my icloud email accounts disappeared. How do I get it back? I tried to add an account in Mail preferences, but at first it wouldn't let me. Today it let's me add it, but the account won't work.

I use Time Warner cable for internet service and icloud.com