Linux Setting up a Mailserver on a subdomain

At work we will be getting a static IP with a subdomain, so if work is example.com, we will be hr.example.com.

Is it possible to set up our own mailserver and have @hr.example.com addresses?

If so, are there any industry standards for mailservers? You know, as Apache is to webervers [blank] is to mailservers.

Are there any conflicts or requirements to setting up a subdomain account?