Two well known companies in my country persist in making the mistake of writing their mid with a non-public fqdn, violating the rfc. It has been so for the past three years, with me sending detailed, manually written error messages to their painstakingly collected admin addresses. Their answer is that everybody else accepts their invalid mid, and their servers are enterprise ibm / microsoft shitware that they are unwilling to fix. Since we get a lot of their emails, I decided to scale up their problem. There are many blacklists, and I have no intention to go through each idiosyncratic procedure.
Is there an ombusdman that superintends the major blacklists and enforces rfc compliance through them?
