It can be anything! An apex, subdomain, or even a URL.

Results formail.xtom.email

Resolver

Location

A

Name	TTL	Value
mail.xtom.email	600	185.255.55.77Xtom / xTom GmbH

Name	TTL	Value
mail.xtom.email	600	2a0c:59c0::77 / xTom GmbH