| > The reason Message-ID is SHOULD rather than MUST? Mail clients > sometimes send messages without one to their submission server, which > adds it on their behalf. As for why Google enforces it anyway: > spam. Messages with minor RFC violations are far more likely to be > spam, so rejecting them is a reasonable heuristic. In practice, Google > and Microsoft have become the de-facto standards bodies for email — > what the RFCs say matters less than what their servers accept. Surely the problem is on Google's end? And a metaproblem is that we are allowing corporations to change or ignore standards for critical infrastructure? |