It's a relatively steep learning curve if you're not getting paid to do it. However, in my case, I have been running my personal mail server on a trusted VPS host for well over a decade now. After the initial setup, there is really nothing to do except for regular Linux updates/upgrades. I run postfix, dovecot, roundcube, and rspamd. All of the configuration is in Ansible, so if the host goes tango uniform, or if I want to move it elsewhere, downtime should be minimal.

There are a few open-source one-command mail server deployment solutions that do all of the heavy lifting for you. Some of them might even be pretty good. The problem with those is that if you don't understand how your mail server is put together, you're completely stuck if it breaks.