There is a bug in the creation process for Dynamic Distribution Groups (DDG) in Exchange 2010. When you use the Exchange Management Shell to create a DDG and specify the Organizational Unit (OU) where the DDG should reside in Active Directory, you must also specify the –RecipientContainer to search for that DDG. Otherwise the DDG Recipient Container defaults to the OU where the DDG was created.

One of my customers came to me with this question. Here is a sample DDG that I created in my lab using the same PowerShell cmdlet that they were using. Apparently, this had worked for them in the past.

New-DynamicDistributionGroup -Name "Abbeville Office" -OrganizationalUnit "" -RecipientFilter {((recipienttype -eq "usermailbox") -and (office -eq "Abbeville Office"))}

Notice that the Recipient Container matches the OrganizationalUnit where it was created. You can also see this in the EMC. This can be changed here or through the Set-DynamicDistributionGroup cmdlet in PowerShell. You will also notice that Exchange 2010 adds some additional information to your query, for example, to exclude Arbitration Mailboxes, Discovery Mailboxes, etc.

You can audit all of the DDGs using the following cmdlet.

Get-DynamicDistributionGroup | select name,RecipientContainer,OrganizationalUnit

Here is the new cmdlet you should be using when creating DDGs:

New-DynamicDistributionGroup -Name "Abbeville Office" -OrganizationalUnit "" –RecipientContainer "" -RecipientFilter {((recipienttype -eq "usermailbox") -and (office -eq "Abbeville Office"))}

This will allow the DDG to search the entire directory for recipients that match your search criteria.