Managing a distribution group in Exchange 2007 works little differently than it did in Exchange 2003. In Exchange 2003, you could select a user to manage a distribution group, and select the option so that they could update the members in the list. (see image below)
In Exchange 2007, you have the ability to select a manager to manage the members of the list as well. However, the manager has no rights to add/remove members from the list. (see image below)
In order to grant this permission to the user, you have to run the following command from the Exchange Management Shell:
Add-ADPermission -Identity:'Group Display Name’ -User:domain\username -AccessRights ReadProperty, WriteProperty -Properties 'Member'
Make sure you have the appropriate permissions before you run that command, or it will error out. According to the Technet article, you will need the following permissions to run the command successfully:
1) Exchange Recipient Administrator role.
2) Account Operator role for the applicable Active Directory containers.
