You have a Microsoft Exchange Server 2010 Client Access server in an Exchange Server 2010 environment.
A domain controller is installed on a different server in the environment.
User A’s mailbox is hidden from the Exchange address lists.
User B configures Microsoft Outlook to connect to the Microsoft Exchange account in online mode.
User B creates an email message by using Outlook. User B enters the LegacyExchangeDN attribute of user A’s mailbox as the recipient address. For example, user B enters "/o=OrganizationName/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=User A’s mailbox" in the To box of the message.
User B tries to resolve the recipient address by clicking Check Names or pressing Ctrl+K.
In this scenario, user B receives the following error message:
Microsoft Office Outlook does not recognize ' / o=OrganizationName/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=User A’s mailbox '
The expected behavior is that user B can resolve the recipient address successfully.
This issue does not occur if the Exchange Server 2010 Client Access server and the domain controller are installed on the same server.
This issue occurs because Outlook uses the Address Book service on the Client Access server to resolve the LegacyExchangeDN attribute of a user’s mailbox. However, the Address Book service filters out hidden users incorrectly. Therefore, Outlook cannot resolve the LegacyExchangeDN attribute.
To resolve this issue, install the following update rollup:
2685289 Description of Update Rollup 3 for Exchange Server 2010 Service Pack 2
Note This hotfix resolves this problem for an Outlook client that is configured to connect to the Microsoft Exchange email account in online mode. For more information about how to open a hidden mailbox in Outlook 2010, click the following article number to view the article in the Microsoft Knowledge Base:
2752427 You cannot use the LegacyExchangeDN value to open a hidden user's shared folder
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 share an Outlook calendar with other people, go to the following Microsoft website: