I'm very new to linux. Yesterday i was firstly installing Ubuntu Server.
My ubuntu server is the only server I have in my home network, and i have neither a local domain nor a domain controller in my network.
Now I'm trying to understand the Postfix mail service.
I have an internet domain I've purchased some years ago.

Does Postfix force my server, wich is also a mail server, to belong to a domain name or I can use it without have a local domain?