After the Exchange 2010 SP1 Install, I have rerun setup /preparead and setup /prepare schema to recreate the user, which is showing up in AD as MsExchDiscoveryMailbox {D919BA05-46A6-415f-80AD-7E09334BB852} When I try to recreate the system mailbox by using Enable-Mailbox "MsExchDiscoveryMailbox {D919BA05-46A6-415f-80AD-7E09334BB852}" -Arbitration, it throws the following error: The operation couldn't be performed because object 'MsExchDiscoveryMailbox {D919BA05-46A6-415f-80AD-7E09334BB852}' couldn't be found on 'mydc.mydomain.com'. + CategoryInfo : NotSpecified: (0:Int32) [Enable-Mailbox], ManagementObjectNotFoundException + FullyQualifiedErrorId : E9E0469,Microsoft.Exchange.Management.RecipientTasks.EnableMailbox Any ideas?

You have to use the -discovery switch when creating or enabling a discovery mailbox.

Ok, I have done that and received the following results, and the mailbox shows up in my list of mailboxes. Name Alias ServerName ProhibitSendQuota ---- ----- ---------- ----------------- DiscoverySearchMailbox... DiscoverySearchMa... wireexchange 50 GB (53,687,091,200 bytes) However, when I look at disconnected mailboxes, there is still a discovery search mailbox listed. When I try to connect it, the discovery search user does not show up, and I don't see a way to delete it. Is it safe to get rid of it? And if so, how do I do that?

Hi, It has no impact when you search in ECP if you make sure the search mailbox has already been list in the recipient node in EMC. And per my test, we cannot reconnect a discovery mailbox. The types of mailbox we can choose are user, room, equipment, linked, archive and shared mailbox. Here is more information, Connect-Mailbox: http://technet.microsoft.com/en-us/library/aa997878.aspx Best regards, SerenaPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Ok, that is fine, but how do I get it to stop showing up under disconnected mailboxes then?

Hi, By default, Exchange retains a disconnected mailbox for 30 days. That means, after 30 days, it will be purged. And during the 30 days, the disconnected mailbox can be deleted permanently by running Remove-Mailbox. For detailed, please see, Understanding Disconnected Mailboxes: http://technet.microsoft.com/en-us/library/bb232039.aspx Best regards, SerenaPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.