To be clear, none of the issues I was seeing were in any way caused by my incompetence. I had MX records, SPF records, DKIM signing, and still Google can arbitr

To be clear, none of the issues I was seeing were in any way caused by my incompetence. I had MX records, SPF records, DKIM signing, and still Google can arbitrarily decide to pass some of my mail through, and then refuse (or worse, hide) the fourth reply in an exchange with a customer. I wanted to clarify that because the above comment makes the issue seem less important. It is important.