comcast email not working on my iphone

I have read many threads and tried everything but I continue to get a message that says my password is incorrect for my comcast email. I checked my portal settings, they're right. I deleted and reinstalled my mail app. I've changed the password. I cannot get anything to work. It was fine last week and one day started giving me the message about the incorrect password. I can log in to get email on my computer but can't get it on my iphone. I'm beyond frustrated.