Why is it recommended to raise a mail server on a freshly installed OS?

Question

Mail server

It is required to raise the mail server, I already seem to have googled mana, but it says they say you need to put it on a pristine clean server.
Why? And what happens if I upload a mail server to a server that has been running for ~ a year as a web server?

Answer 1

You may encounter a bunch of hard-to-diagnose and extremely difficult-to-fix problems. Plus, do not forget that OS security is one thing, the security of the OS system + mailer is another, and the security of a tangle of software with muddy dependencies is the third.