I'm familiar with this article. I run my own email servers for more than a decade on both VPS and physical servers. If you want 99.99% deliverability you have to give up self sovereignty and stick with gmail. If you're ok with 99% deliverability and not sending spam aka "newletters" then self hosting is fine. Good workaround is to use individual websites contact forms when sending an initial inquiry/request then the followups are easier.