Unable to send email do to lack of reverse dns

@user_f2w8mj Do you pay for a static IP address with Comcast? If not, they will not be able to complete a reverse DNS request on a dynamic IP address. Even if they set up a reverse DNS, without a static IP address, as soon as your IP address releases and renews (typically every 14-30 days), you will be back in the same position. Static IPs are required for a permanent reverse DNS fix.

I hope this helps.

Thank you for reaching out to us here @user_f2w8mj. I would be happy to assist you from here with that request. 

To send a direct message [private message]:

   Click the "Direct Message" icon or  https://forums.xfinity.com/direct-messaging

   Click the "New message" (pencil and paper) icon

   The "To:" line prompts you to "Type the name of a person". Instead, type "Xfinity Support" there.

   - As you are typing a drop-down list appears. Select "Xfinity Support" from that list.

   - An "Xfinity Support" graphic replaces the "To:" line.

   Type your message in the text area near the bottom of the window

   Press Enter to send it

FWIW. Static IP addresses can only be assigned to Business Class subscribers. And one must also use their supplied Business Class gateway device in order for the static IP(s) to be able to route from the WAN to the LAN of the device