I recently moved all of the user mailboxes to a new database after the existing db reported having reached its Named Properties limit. I would now like to offline (i.e. dismount and remove) the old mailbox database but I noticed the system attendant mailbox is located on it.Do I need to do anythingto account for the SA mailbox on this database before I offline it?I*think* Exchange 2007 will automaticallycreate a new SA mailboxonce I've remove the db where it currently resides but I'd like to *know* before doing it.We're runningExchange 2007 SP1 in a Single Copy Cluster (SCC), if it matters.Thanks.-Lance

No, you don't have to do anything, Exchange will recreate System Attendant mailbox on next available database when you remove first database. Amit Tank | MVP - Exchange | MCITP:EMA MCSA:M | http://ExchangeShare.WordPress.com

Hello, When you run Exchange setup for the first time we will always create a default storage group and default mailbox database (also depending on installation order you may get a second storage group with a public folder database). This default database serves several purposes: 1) In order for the information store service to start there must be at least one storage group and one mailbox database defined.2) The system attendant mailbox defined for the server is automatically stored in the first mailbox database created during setup.3) Each storage group has a system mailbox. When the default mailbox database and/or storage group are removed and recreated, the homeMDB associated with the system mailbox and system attendant mailbox are no longer valid. When a storage group and database are recreated, the system mailbox should be created and the system attendant mailbox rehomed to this store. The issue here is when these operations fail. When any of these operations fail, the following operations may also fail: 1) Move mailbox may no longer function.2) OWA free busy publishing may no longer function.3) Event sinks may not function correctly if the system mailbox is absent.Exchange 2007: Renaming the default storage group / mailbox database or deleting and recreating. In most cases the rehoming and recreation procedures work without issuesMore information, description & Source of the above information.http://blogs.technet.com/timmcmic/archive/2009/04/12/exchange-2007-renaming-the-default-storage-group-mailbox-database-or-deleting-and-recreating.aspxArun Kumar | MCSE - 2K3 + Messaging | ITIL-F V3