Your email client is unable to reach the imap server for comcast.net. Either a network connection issue or imap server issue itself. There are other customers reporting email issues in this Community Forum as well, but not all users. What is the zip code where you are experiencing the issue? If you use a command prompt and do a tracert imap.comcast.net it might show how far thru the internet it gets and the route. Post a screenshot if you can and maybe it will help Technical Support.