How do you add a fictional domain to Microsoft Exchange on-premises as an accepted domain? This placeholder domain does not correspond to a real domain.

Procedure

1. Open the Exchange Administration Center (EAC).
2. Sign in as an administrator.
3. In the left-hand menu, select Mail flow.
4. Select accepted domains.
5. Click add to add a new domain.
6. Enter a name, for example Zivver Relay.
7. For Accepted domain, enter zivver.org.
8. For This accepted domain is, choose Authoritative.
9. Click Save.

The placeholder domain is now listed as an Accepted Domain in Exchange.