> If you have a deployment that can speak the languages of IMAP and SMTP and the many anti-spam tools, you are de facto part of the global email social network

> If you have a deployment that can speak the languages of IMAP and SMTP and the many anti-spam tools, you are de facto part of the global email social network It takes too much effort and time to actually have reliable email server. One mistake in config or wrong thing good luck convincing MS and Google. Even smaller players like fastmail and proton (many others) will have problems with Gmail or Outlook (Hotmail or whatever the hosted version of MA offering is called now) from time to time. The language of anti-spam tools for any practical reason in this space is defacto unknown to you. So you don't know what is actually this language.