When the first Exchange Server 2007 server is installed in an existing Exchange Server 2003 organisation, the installation automatically adds any domains that are enabled in the Exchange 2003 recipient policies to the Accepted Domains list in Exchange Server 2007. However, domains that are not enabled (such as @test2.local) are not added to the Accepted Domains list.
This creates a warning condition when you view the Email Address Policies in Exchange Server 2007.
If you then add another domain to the Accepted Domains list in Exchange Server 2007, you are not able to remove it again while this condition is in effect. Here I’ve added @test3.local to the Accepted Domains list, and then attempted to remove it again. In the real world this might occur if you were adding a domain to the list for testing purposes only, and then wished to remove it.
The error also occurs if you are attempting to remove it via PowerShell.
[PS] C:\>Get-AcceptedDomain DomainName DomainName DomainType Default ---- ---------- ---------- ------- testing.local testing.local Authoritative True test1.local test1.local Authoritative False test3.local test3.local Authoritative False [PS] C:\>Remove-AcceptedDomain test3.local Remove-AcceptedDomain : The accepted domain 'test3.local' cannot be removed or made external because it is referenced by the e-mail address policy templates 'smtp:@test2.local'. At line:1 char:22 + Remove-AcceptedDomain <<<< test3.local
The error message does not tell you which Recipient Policy is the cause of the issue, it only informs you of the disabled domains that the Recipient Policy (or policies) contain. In a complex Exchange organisation this can make it difficult to track which ones require attention. However you can refer to the warning message that appears when you view the Email Address Policies to give you clues as to which Exchange Server 2003 Recipient Policies contain disabled domains.
To resolve the condition, you must remove the disabled domains from the Recipient Policy.
Once this has been done you can refresh your view of the Exchange Server 2007 console and the warning no longer appears on the Email Address Policies.
You can now remove the domain from the Accepted Domains list in Exchange Server 2007 either by using the management console or via PowerShell.
[PS] C:\>Remove-AcceptedDomain test3.local Confirm Are you sure you want to perform this action? Removing Accepted Domain "test3.local". [Y] Yes [A] Yes to All [N] No [L] No to All [S] Suspend [?] Help (default is "Y"): y [PS] C:\>Get-AcceptedDomain Name DomainName DomainType Default ---- ---------- ---------- ------- testing.local testing.local Authoritative True test1.local test1.local Authoritative False