As of 2014, Comcast customers can access their email messages by using the "Sign In" link on the Xfinity website. The link is clearly labeled and is located at the top of the page.
One can read and write email messages after using the "Sign In" link and entering a valid Comcast email address and password. Comcast offers an integrated login feature, allowing customers to access other services such as voicemail without needing to reenter a password.
Customers should think about security when using Comcast's Web-based email interface. The "Keep Me Signed In" check box on the login page can offer convenience but may also represent a potential security risk on a shared computer.