The email is full of bugs. For one thing I can't click on a link. I can open in another tab. You can't return to email from the address book.
If you try to get answers from Comcast they want to chat with you. this is where they put the techs they just brought over from delivering newspapers. Instead of saying they know about the problems, they are working on the problems, they want to "chat" with you. Waste of time. Once they want to chat, they're already showing they don't get it.
The link issue is known, and is down to Google if you are using Chrome as your browser. See here for more detail---------------
Until they get it fixed, you can try disabling the pop-up blocker in Chrome. OR-----right-click the link to open it in a new window or tab. OR------drag and drop the link into a new tab in the browser's tab bar.
In the Address Book, just look to the left of "Address Book" in the upper bar and Mail should be there. Just click on it to get back to the Inbox.