gmail-->xfinity forwarding -- not longer forwarding accurately

This is irrelevant to my situation, because the forwarded Gmail messages are never reaching my Comcast mailbox; I do not have any trouble retrieving email from Comcast. The problem is that the mail system is rejecting emails that are automatically forwarded from Gmail (in some cases because it has suddenly decided that the emails constitute spam). 

Hello, @user_xn26w1 I appreciate the confirmation that the previous link wouldn't be helpful. Investigating further since you had mentioned you were receiving error messages/codes, I found this document on our website: https://www.xfinity.com/support/articles/email-errors

For most of the codes/messages outlined on the article, this looks like it will need assistance from our Customer Security Assurance experts: https://spa.xfinity.com/help [Edited: added correct URL]

- Have you contacted that team? 

Tell me how!? All I could find on that page was a useless FAQ (for my situation) and a response form with a limited number of issues and no option to get help for "other" issues. I am not a postmaster.

@user_xn26w1 the "Postmaster" is section on the website you want to select > scroll down to the bottom of the page > select "report an issue" > The "I'm not able to send e-mail to Comcast customers" is the option from the drop-down to select since it's the closest to the specific concern. There will then be some question to fill out as it looks like it may want the specific error messages that populate. 

I tried that. The response system claims that the sender IP address is not blocked -- but Comcast keeps deflecting emails forwarded from Gmail, claiming that the various dynamic DNS addresses used by the Google email servers are either "on one or more DNSBLs" or "listed on the Return Path Reputation Network Blocklist." Obviously, a problem way above my purview as a mere user!