I self-host using machines literally under a desk in my home. I've had the setup since 2010.
For sending SMTP, I use the SMTP forwarding host operated by my ISP.
You do not want to be chasing a solution where the same machine that runs all your self-hosted stuff is also sitting on an IP address with a good SMTP-sending reputation.
Have your hosting machine wherever it is convenient for you, and find it a good SMTP forwarding host.
The only downside about forwarding is that the forwarding host or chain of hosts can intercept your plain-text e-mails. The good thing about direct SMTP is that you can use TLS to connect to the target domain to which you are sending e-mail, so you don't need PGP in order to thwart eavesdropping.
However, the security benefit of TLS and direct sending is somewhat negated by most people's mailboxes being hosted by large providers like Google which read their mail.