How to create a a fictional domain to Microsoft Exchange on-premise as an accepted Domain? This is a placeholder domain that does not refer to an existing domain.

Procedure

1. Go to the Exchange Administrative Center (EAC).
2. Log into EAC as an administrator.
3. Go to mail Flow in the menu on the left.
4. Go to accepted domains.
5. Click the add button to add a new domain.
6. Enter a name. For example: Zivver Relay.
7. Specify the accepted domain. Use zivver.org as the accepted domain.
8. Select for This accepted domain is the option Authoritative.
9. Click Save.

The placeholder accepted domain is now created as an Accepted Domain within Exchange.