Salam, I've been able to remove all roles from my exchange 2010 server except for the mailbox role, when I try to remove the System Mailboxes its giving the hereunder error, also note that the installation of the exchange 2010 was transitional, as in I still have an Exchange 2003 legacy server and I want to remove the current exchange 2010 installation and do a new fresh one. [PS] C:\>Get-Mailbox -Database DB2 -Arbitration | Remove-Mailbox -Arbitration -RemoveLastArbitrationMailboxAllowed The arbitration mailbox "arabfinancehouse.com.lb/Users/SystemMailbox{e0dc1c29-89c3-4034-b678-e6c29d823ed9}" is used by Exchange and can't be removed. + CategoryInfo : NotSpecified: (arabfinancehous...8-e6c29d823ed9}:ADObjectId) [Remove-Mailbox], Recipient TaskException + FullyQualifiedErrorId : B61A49E4,Microsoft.Exchange.Management.RecipientTasks.RemoveMailbox The arbitration mailbox "arabfinancehouse.com.lb/Users/FederatedEmail.4c1f4d8b-8179-4148-93bf-00a95fa1e042" is used by Exchange and can't be removed. + CategoryInfo : NotSpecified: (arabfinancehous...bf-00a95fa1e042:ADObjectId) [Remove-Mailbox], Recipient TaskException + FullyQualifiedErrorId : F62F1855,Microsoft.Exchange.Management.RecipientTasks.RemoveMailbox Thank you in advance, Kindest regards.Abdullah^2

Hi, Please try this: 1. Start the Active Directory Users and Computers snap-in. 2. On the View menu, make sure that Advanced Features is selected. 3. Locate the Microsoft Exchange System Objects container. 4. Delete the SystemMailbox{e0dc1c29-89c3-4034-b678-e6c29d823ed9} item Regards from www.windowsadmin.info

Salam, Thank you for your swift reply, actually I couldn't find that SystemMailbox in active directory. I only found SystemMailbox{26067197-3BBD-4AB8-BB13-3EF725B3605A} and SystemMailbox{dbb0180a-8464-42d6-8af3-bcf911e868a9}. I don't recall doing it, but in case I deleted that object in a previous tryout probably from ADSIEdit would that be a problem? Thank you, Kindest regards.Abdullah^2

Hi, You may use ADSIEDIT or LDP.exe to find and remove the mailbox directly from AD. Regards from www.windowsadmin.info

Salam, Yes I understand that, but what if I can't find that SystemMailbox? On the other hand could you point me on the steps on how to remove it using LDP please. Thank you, Kindest regards.Abdullah^2

Hi, Please check this blog to remove system mailbox http://blogs.microsoft.co.il/blogs/dand/archive/2009/06/24/quot-one-or-more-users-currently-use-a-mailbox-store-on-this-server-quot-when-trying-to-uninstall-exchange.aspxRegards from www.windowsadmin.info

Salam, Thank you for the above link, it was pretty informative and did the trick. On the other hand could you please help me in one more thing, there is still the public folder and its giving me an error about replication when trying to remove it. Knowing that the first thing I did before uninstalling Exchange 2010 is I remove replication from the Exchange 2003 server and I currently have only the Legacy server in replication alone with no public folder which is related to the Exchange 2010. Any idea? Thank you, Kindest regards.Abdullah^2

Hi, Did you installed latest service pack and tried?Regards from www.windowsadmin.info

Salam, I am on the latest I think, isn't Exchange 2010 SP1 is the latest release? Kindest regards.Abdullah^2

Hi, If you are running with SP1, it is not an issue related to updated files. I am unable to solve the issue because I am not getting the exact issue. Anyway I think this link http://blogs.technet.com/b/bill_long/archive/2010/04/22/fixing-public-folder-replication-errors-from-exchange-2003-to-exchange-2007-or-2010.aspx may be helpful. Refer here also http://msexchangeteam.com/archive/2006/01/23/417974.aspxRegards from www.windowsadmin.info

Salam, As I've read in the KBs you've given, they're meant to fix replication between Exchange 2003 and Exchange 2007/2010. Yet my intention is to remove the current public folder database on Exchange 2010 so that to commence with uninstalling it. Thank you, Kindest regards.Abdullah^2

Salam, Never mind now, I managed to delete the public folder database from ADSIEdit (of course I am certain the everything was replicated back to Exchange 2003 successfully). Thank you very much for your help and support, Kindest regards and most respect.Abdullah^2