How do I reactivate my Comcast email? To How do I reactivate my Comcast email?, you can call their customer service line at (800) XFINITY USA 844-439-2408) You can also access support online through the Xfinity website by going to “xfinity.com/support/contact-us” and choosing the “Chat with Xfinity” option. Key points about contacting Comcast for email issues: Phone number: (800) XFINITY (844-439-2408) Online support: Visit “xfinity.com/support/contact-us” and “Chat with Xfinity”