> Also on IP reputation. I think there's something off here. IP-reputation is largely a thing of the past. IP addresses are ephemeral and email providers unde

> Also on IP reputation. I think there's something off here. IP-reputation is largely a thing of the past. IP addresses are ephemeral and email providers understand that. Especially with IPv6, where an individual can have access to tens of thousands of addresses. So, all large email service providers have spam filters based on content, and domain reputation, not IP reputation. Misbehaving hosts may be periodically blocked based on IP, but this is never permanent. Otherwise email providers would be blocking the entire IPv4 internet by now. If you have a domain that does not spam, and it is using DMARC + DKIM, then there is sufficient proof that an email sent on behalf of the domain is authentic and the email will be accepted no problem. The only real problem with hosting your own email, is that it is usually impossible to host it from your residential internet connection, as ISPs do not allow you to 'own' your IP-address, by not allowing you to create PTR records. This is all on purpose though, ISPs block it and email providers require it. It's is because there are just so many residential IP addresses that are part of a botnet sending spam.