Using Exchange 2007 SP1, Outlook 2007 SP1 We are having an issue where UserA is trying to add UserB as a delegate to their mailbox and receive the error "The user UserB can not be added. Non-local users can not be given rights on the server". The issue can be resolved by changing UserB's mailbox type from SharedMailbox to UserMailbox ( Set-Mailbox UserB -Type Regular). Doing a query, I've found out that I have 195 SharedMailboxes. What is the definition of a SharedMailbox -- i.e., what does it do? What is the impact of changing from a SharedMailbox to a UserMailbox? Is there any reason I shouldn't do this for all 195 user accounts? I recently migrated from Exch2003 to Exch2007. Online search says it sometimes happens that mailboxes show up as shared after a migration.

Hello Chad,The below link would give you solid knowledge about all the different type of Mailboxes we have in Exchange 2007 Server!First class recipient types in Exchange 2007 http://msexchangeteam.com/archive/2006/10/26/429365.aspxArun Kumar | MCSE - 2K3 + Messaging | ITIL-F V3

This is known migration issue, it happens when user has Associate External Account permission assigned to Self in Mailbox permission before migration and after moving mailbox it shows shared mailbox. It is safe to convert to user mailbox since those are used by only one user who owns it.Amit Tank | MVP - Exchange | MCITP:EMA MCSA:M | http://ExchangeShare.WordPress.com

In Exchange 2003 and Exchange 2000, you had to use shared mailboxes to represent resources. When you move these mailboxes to Exchange 2007, they will be Exchange 2007 shared mailboxes ---------Refer to < How to Convert a Mailbox> As Amit said, theres no harm to convert a shared mailbox to user mailbox We can convert all the shared mailboxes to user mailboxes using the following command: Get-Mailbox -Resultsize Unlimited | Where {$_.RecipientTypedetails -eq "sharedmailbox" | Set-Mailbox -Type Regular Resource: Non-local users cannot be given rights to this server (Similar Case)