I share administration duties for a moderately sized exchange environment (1500 accounts) and have found that some tools used by other administrators do not correctly add the user mailbox properties in AD. Specifically, security personnel create accounts that do not have all the adequate properties.
When viewing one of these accounts with Active Directory Users and Computers, the Exchange General tab is present with alias and mailbox information, the Exchange Features tab is present with Mobile Services and Protocols, and the Exchange Advanced Tab is visible. The Exchange Addresses tab is missing.
I have some accounts that have had name changes, and we are unable to rename the SMTP and X.400 addresses properly because of this. In newly created accounts, I simply remove all exchange attributes and re-build the mailbox. This restores the missing properties. In one specific case, however, this is not an option as there is a great deal of mail and appointments in the mailbox that would be deleted. No one can login to this mailbox or even see it in the directory while this problem persists.