Incoming Mail Server
Host Name: mail.comcast.net
User Name: Don't add @comcast.net, just user your user name
Primary Server: smtp.comcast.net
Host Name: smtp.comcast.net
Server Port: 587
Use SSL: Off
Server Port: 110
Despite having all the correct settings on my iPhone and my iPad, Comcast has issues with their email service on many devices. Even Outlook on my Mac of all things. It normally sorts itself out in a hour or so (like they were performing maintenance on their servers).
They just neglect to tell the customers paying for the service which can be frustrating. An alternative is to always try and see if you can get to your inbox via your web browser of choice. Worked for me in a pinch if I was expecting something important.
They used to not support getting email on devices that we not on their network (that is how long I've had them). The last time I looked at their settings page was some time back, and I thought there were a couple of ports that work. Actually, I think it may depend on where you were when you added the account (off their network/not at home versus at home).
Whatever it is, this information should help the OP.
Thanks everyone for your suggestions. I tried everything you suggested and nothing works. I can not receive email. I called Comcast, they gave me similar suggestions and I was discussing the situation with the rep and suddenly lost the connection Did they call me back (since I entered my phone number and they verified it???) that answer would be "no"..
I will try again tomorrow. Again many thanks, I appreciate the support from this community.