I'm self-hosting and I'm using mailgun to solve the delivery issues. Free-tier of up to 1K messages per month is good enough for a personal domain.
Funnily enough, I'm actually working on something (a proxy) that turns the Mailgun API into SMTP/Listmonk[0], since I was annoyed that Ghost only allows Mailgun.
Great to hear they're a solution for this though -- will update my article to reflect them next to ImprovMX.