My IP 188.8.131.52 is blacklisted on Spamhaus Zen and Sorbs Duhl lists.
What is the procedure to have Comcast/Xfinity contact the lists to get me off... or how do I get a new IP? I'm using the Xfinity ARRIS TG1682G gateway.
That's normal for Comcast's residential Internet service. All of their IPs are dynamic and are, or should be, blocklisted. The only way around it is signing up with their Business service or another provider who offers static IPs.
Are you trying to send messages directly to other mail hosts? Or you're sending through the comcast.net relays?
I send mail through my web host / domain, like most other people. https://pair.com.
Maybe their mail servers are on the blacklist? But when I did a lookup on my IP (184.108.40.206) granted to me by Xfinity, it showed up on two of the lists. That does not make sense.