Comment by sylware
12 hours ago
I think DMARC is missing email address with IPv[46] literals support. As being self-hosted, without paying the DNS mob, I am still blocked to send email to gmail.com because such email addresses do throw out of whack gogol code.
Email addresses with IPv[46] literals are intrinsincly stronger than SPF. If in the envelope or any of the 'from' headers (if my memory does not fail me, there are few more headers to scan), the IPv[46] literal does not match the actual and real IP of the SMTP server, the email is dropped, not even going into any spam folder.
Conspiracy mode: they know and are careful not to support that, in order to create a walled garden of internet messaging for them and their friends.
I think DMARC is missing support for homing pigeon characteristics such as the markings and colors on its crest and plumage. As being self-hosted, without paying the IANA and ISP mob, I am still blocked to send email to gmail.com.
Arguably, missing IP literal domain support is pretty far down the list of things creating today's actual mail delivery walled garden.
Wasn't this removed from the email standards?
It is not a conspiracy theory that it is hard to maintain reliable delivery with self-hosting email. It is primarily because email filters are in part based on trust relationships, and huge amounts of spam come (or at least, did) from relatively unknown originating servers.
Most people don't own their IP range so it's moot point to support it.