Self-hosting outbound is almost impossible though, I've yet to find an ISP that's not blocking outgoing port 25. I'm semi-self-hosting outbound and it's an abso

Self-hosting outbound is almost impossible though, I've yet to find an ISP that's not blocking outgoing port 25. I'm semi-self-hosting outbound and it's an absolute nightmare to get the ISP to acknowledge that if they block your packets, they must provide an alternative (smarthost). Also, getting them to register a reverse DNS entry is very difficult, most supporters couldn't tell you the difference between DNS and rDNS if their life depended on it. The technical stuff with SPF and DKIM is the easy part.