I am having difficulty finding information on how to completely noindex only one particular subdomain via htaccess (from my understanding, that's the best way?) and it is important for me that only that one subdomain and its files are never indexed or crawlable.
I have an Apache server that uses Plesk and the subdomain is for an email software we use for newsletter campaigns etc.
The subdomain is "mail" (e.g https://mail.test.com) and my goal is to only make "mail" noindex because for some reason the software has seo features that can wind up harming our general purpose etc.