You're welcome to run your own insecure email server, but don't expect other mail servers to connect to it, or accept connections from it.
Also, don't allow other people to send or receive email from that server unless they have given you their informed consent that it does not meet the basic industry standards for security.
Sure, and servers should refuse to connect and deliver mail to gmail.com addresses without consent from the recipient that their email can be read by Google employees and any government with the jurisdiction to compel them since they don’t offer email encryption.
Your definition of “basic industry standards for security” is not the same as others who are serious about security and it’s not the same as people slinging birding newsletters.
The fact that legal action to fit your taste is being suggested is pretty tone deaf.
Also, don't allow other people to send or receive email from that server unless they have given you their informed consent that it does not meet the basic industry standards for security.