I cannot get icloud mail online -

I have Mountain Lion OSX 10.8.4 and cannot get my icloud email to work. I went to the mail setup to verify the settings as I had already tried to do this and I do not seem to have the right outgoing mail server info and it is greyed out so I cannot change it. I also cannot get it on line. Anyway, can I delete the mail box and start over or how do I fix this? Thanks