You could install a basic setup with a "apt install x x x" one-liner in ubuntu, and it would not take more than a few minutes to configure everything with sensi

You could install a basic setup with a "apt install x x x" one-liner in ubuntu, and it would not take more than a few minutes to configure everything with sensible defaults. The key here probably is, most people don't want to spend time learning enough about Postfix, Dovecot. Etc. To do that.