Several Outlook 2010 users with Exchange 2010 mailboxes reported the following issues.
When creating a new message and adding a Universal distribution list to the To: field, they attempt to expand the membership of the DL and they get an “Cannot perform the requested operation. The command selected is not valid for the recipient. The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action.” error message.
In addition, if they tried to look at the Organization properties of the user, it appears blank and they get an “Unable to connect to retrieve additional data” error as shown below.
While we were troubleshooting the issues, we checked the status of the Microsoft Exchange Address Book services on all of our CAS servers. On one of our CAS servers, we found a problem with the Microsoft Exchange Address Book service. All of the other Microsoft Exchange services on the server were fine. After restarting the Microsoft Exchange Address Book service on the CAS server, users were able to successfully expand the membership of a DL and view Organization information.