Motorola MPx220

I set-up my comcast mail account since I can't seem to get my Gmail account to work. While I configured it to the settings that were given to me by Comcast, I keep getting the following error message after receiving my new emails (yet the 9 new emails have never appeared in my inbox): "The following errors occurred while sending and receiving mail: The message(s) could not be sent. Verify that you have network coverage and that your account information is correct and then try again." Anyone have any suggestions? At least I have gotten further with the Comcast account than I did with the Gamil account.