You grant Full Access permission to a user on a non-user mailbox (such as resource mailbox) in a Microsoft Exchange Server 2010 environment.
You grant the user Send As permission and Write Personal Information permission for the non-user mailbox.
The user tries to add delegates or tries to remove delegates from the non-user mailbox by using Office Outlook.
In this scenario, the user cannot add or remove delegates. Additionally, the user receives the following error message:
The Delegates settings were not saved correctly. Cannot activate send-on-behalf-of list. You do not have sufficient permission to perform this operation on this object.
This issue occurs because Role Based Access Control (RBAC) is involved in the decision whether the user has permission to perform the action. In the scenario that is mentioned in the "Symptoms" section, the user has permission on the non-user mailbox. However, the user does not have management rights over the non-user mailbox.
To resolve this issue, install the following update rollup:
2608646 Description of Update Rollup 6 for Exchange Server 2010 Service Pack 1
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about how to manage Full Access permissions, visit the following Microsoft website: