How many subdomains can you have on your domain? And with that, I mean levels of subdomains.
For example, you have the domain
example.com, I know you can have
test.example.com, but how many levels can you have? Like
Second, I was wondering 2 things about email addresses. First of all, how common is the usage of subdomains in an email address (IF it's even possible)? I've never seen something like
email@example.com to be honest so I'm not exactly sure. And if it's possible, how many levels (just like above) can you have?
And last, can the questions above depend on the domain registrar or the mail server etc.? And what could it depend on?