Basically you need an IP with a good reputation, and a provider who will allow you to use port 25 incoming and outgoing. These two things are the biggest challenges. Otherwise, any provider that offers you a public IP (preferably dual stack IPv4 and IPv6) and Ubuntu 22.04 will do.
See also the discussion here: Clean Hosting Providers? - #3 by sugumaranv
Personally, I run my server here and never had any issues.