Getting a fixed IP address is really easy, and cheap. I for example have one with my residential internet connection for another $5/month. You also get one with almost all VPS/Colo/etc hosting.
I think you are misunderstanding the tech here.
Can you explain what you meant about the tech? I am actually curious about hosting my own email. I think what I was referring to was the first reply on HN. Specifically this comment:
"The primary issue brought up is deliverability. If you don't have a static IP, or you don't have control over your reverse DNS PTR, or the reputation of your IP is poor, then pay a company to smarthost your outgoing mail through them. It's a few $ a month, and poof! Problem solved.
By that "logic" self-hosting is easy because I could have a third party handle outbound AND inbound mail, which is essentially standard mail hosting with a custom domain.
Plus you cannot just turn-key create a high reputation, you start out with low and your emails will be dropped into spam."
reply
That's suggesting an option to get around not having a static IP. The other option is to just get a static IP. That's not difficult or expensive.
reply
I'm on a mission to price options in my area
reply
Are you familiar with the term "colocation"? That lets you put your hardware in someone else's data center. Most cities have colo hosting available.
reply