admin moves user from exch2003 to 2007. mailbox is identified as legacy in the console

synopsis: 
user(admin) moves a user from exchange 2003 to exchange 2007 using exchange 2007 console, the moved mailbox shows up as legacy mailbox and user is not able to login

Error:
Although the mailbox was moved to the target Exchange server, an error occurred while the policies were being applied. Proxy address policies, Unified Messaging settings, managed content settings, and Exchange ActiveSync settings may not be set correctly. Active Directory operation failed on server. This error is not retriable. Additional information: Insufficient access rights to perform the operation.

resolution:
Using powershell, run
set-mailbox alias -applymandatoryproperties
user will now be able to logon