How do I block an email address and how do I eliminate my email address?
To block a sender------------
Scroll about halfway down the page for blocking instructions.
As for your own email address, it is the sign-in credential for your Comcast account. So you have to have one even if you don't use it for anything else. You can also change it if you like----------------
Yes, you can change the user ID-----that portion of the email address to the left of the @ symbol. On the Xfinity home page, click on "My Account" at the top. Sign in again. On the top of the landing page, click on "Users". The account name should now show. To the right, click on "Edit", and follow the prompts.
Caution-----once you change the user ID, you CANNOT get the old one back. So make sure the new one is really what you want.