Outlook issues when the msExchMasterAccountSID attribute exists on a user account in Active Directory
Original KB number: 2996202
After a mailbox move or migration, one or more of the following issues may be displayed:
Some mailboxes show as linked or shared rather than as user mailboxes.
Repeated mailbox credential prompts in Microsoft Outlook or Outlook Web App (OWA)
Unexpected delays in, or halted mail flow.
Problems accessing Public Folders, and sometimes resulting in the following error:
Cannot expand the folder. Microsoft Exchange is not available. Either there are network problems or the Exchange Server is down for maintenance.
This behavior can occur if a regular user account has the
msExchMasterAccountSID attribute populated in Active Directory.
To correct this issue, run the following PowerShell command from the Exchange Management Shell:
Set-User -Identity useraddress -LinkedMasterAccount $null
Set-User -Identity firstname.lastname@example.org -LinkedMasterAccount $null
This command will remove the
msExchMasterAccountSID attribute from the user's account.
msExchMasterAccountSID attribute shouldn't exist for a regular user account in Active Directory. A regular user will be identified as having an
msExchRecipientTypeDetails attribute value of 1 (1 = normal mailbox, 2 = linked mailbox.)
If msExchRecipientTypeDetails = 1, then
msExchMasterAccountSID shouldn't exist on the account in Active Directory.
For more information on possible values for the
msExchRecipientTypeDetails attribute, see the following Office 365 blog post: