Comcast mail contact

Anyone from Comcast on this list? would appreciate if you can reach
out off the list. Have a few concerns regarding Comcast servers
intermittently throwing 550.5.1.0 -- invalid domain errors.


You can reach out to me privately if you'd like. Typically those are related to DNS being unable to resolve an MX/A/AAAA for your 5321 Mail From domain, but I can take a better look to be sure.