Hi-We run 2 Node Exchange 2003 Cluster with AD 2003 Mixed mode.We accidently deleted the SystemMailbox object from AD, We again restored the Account from our Commvault backups, When i Look in ESM there are 0 Items in the Mailbox, We have an issue with Symantec Enterprise Vault Plugins (which made us note that the SystemMailbox was deleted) and when Symantec Support told us that the SystemMailbox should have some mails which is the root cause for the issue. i am not able to find the Backup of the Systemmailbox on my Commvault Backups, is there any way to restore or recreate the Mailbox.

use LDP to GUID value of the store and then manually recreate the account. Refer MSKB http://support.microsoft.com/kb/316622 for steps

Dismount and remount the store, when you do this the IS store checks to see if the system mailbox exists and if it doesn't it creates one based on the AD object.James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

Not really, Because the system mailbox is associated with the database. One option you have is to create new Database and Move the Mailbox. Post the resultGulab | MCITP: Exchange 2010-2007 | Skype: Gulab.Mallah | Blog: www.ExchangeRanger.Blogspot.com

1. Read this KB http://technet.microsoft.com/en-us/library/aa996235(EXCHG.65).aspx 2. There are several links in there which will help you re-create the mailbox and give you a good understanding. Also explains the items which are missing from that mailbox. 3. Whenever you mount a mailbox store, one of the checks it runs is whether a SystemMailbox{guid} object is in place. If it cannot find one, it looks in the directory for the SystemMailbox{guid} directory object within the MESO container, and then creates the SystemMailbox{guid} mailbox object within the mailbox store. 4. If it can't find the guid then follow the kb mentioned above and eknath which is also on the link in step 1.Sukh