[pjd7]

Overall the changes seem sensible. For those wanting to self host there are plenty of guides out there on how to configure various MTAs with all of the required bits.

BUT, Why does IP reputation matter so much these days when you have DKIM, MTA-STS, DANE and other mechanisms that provide verification of the sender?

Say I want to startup a Email Service Provider, I need to go and source a bunch of IPv4 typically to have a premium upsell for end users to really ensure cross sender reputation does not impact other tenants. Crazy.

IPv6 historically at least was anecdotally punished by the likes of GMAIL, Yahoo, Hotmail, Office365 etc. Does anyone know if IPv6 hosted email severs still suffer additional spam scoring?

[U8dcN7vx]

Delivery via IPv6 still seems more stringent. IPv4 now requires "authentication" as well where previously only IPv6 did. Last I checked Google didn't use DANE, preferring instead MTA-STS -- perhaps understandable for a giant web property.