I’ve been running my own email server for 15+ years. One year ago I needed to change VPS providers and thus get a totally different IP. I worried about this a bit, but actually had no issues whatsoever. Of course, I wasn’t starting completely from scratch as I had the same domain, all my personal experience, and a battle-tested configuration for docker-mailserver. But yeah, the lack of IP reputation itself didn’t seem to be an issue at all. Maybe I got lucky. Or maybe it’s because I chose a relatively small Canadian VPS provider rather than one of the global cloud giants (I assume their IP address space gets pretty trashed with scammers).