I've read that the legacyexchangedn attribute is used in Exchange 2007 for compatability with legacy clients. Is there anything else that it's still needed for? In exchange 2003 it was needed for replyability. If a mailbox was deleted and re-created, I had to add the legacyexchangedn attribute as an X500 address. Will this no longer be the case in native mode? Just curious, thanx.

Dear customer: Exchange 5.5 used Distinguished Names (DN) to uniquely identify objects in its directory. DNs are part of the X.500 directory standard. Active Directory also uses DNs but in a slightly different format to 5.5. In addition Exchange 2000 continues to use Exchange 5.5 style DNs for its objects which are stored in AD. So, in summary, an Exchange 2000 object stored in AD will have an AD style DN which is stored in the dn attribute, and an Exchange 5.5 style DN which is stored in the LegacyExchangeDN attribute. Most objects in Exchange carry this attribute, and its structure is based on the 5.5 directory hierarchy. Mailboxes, for example, have the following LegacyExchangeDN structure: /o=Organisation/ou=Administrative Group/cn= Recipients/cn=Username So for example a user called Fred, in the Microsoft organisation in the Europe Administrative Group would have the following LegacyExchangeDN: /o=Microsoft/ou=Europe/cn=Recipients/cn=Fred None recipient objects also carry a LegacyExchangeDN attribute. So for example, a server called LONDON in the same Admin Group as Fred would have the following LegacyExchangeDN: /o=Microsoft/ou=Europe/ cn=Configuration/cn=Servers/cn=LONDON In addition, all versions of Outlook use the LegacyExchangeDN property when a user delegates access to folders by using the Outlook client. If you delete the legacy administrative group that the LegacyExchangeDN property references, Outlook will not be able to find the assigned delegated user. Hope it helps. Rock Wang - MSFT