Event ID 9548 is logged for Disabled User Accounts which do not have a master account SID

The steps that are provided in this section are for disabling Active Directory user accounts that have Exchange 2000 mailboxes or Exchange 2003 mailboxes. If you follow these steps when you disable the account, event 9548 is not logged. If only a small number of mailboxes are exhibiting this problem, you can generate anmsExchMasterAccountSID attribute. To do this, follow these steps: In the Active Directory Users and Computers snap-in, on the View menu, click Advanced Features. In the Exchange Advanced properties of the disabled user object that owns the mailbox, click Mailbox Rights, and then search the list of accounts for one that has the Associated External Account permission. If no account has this permission, grant the SELF account Associated External Account and Full Mailbox Access permissions. Note The SELF account is available in all Windows 2000 domains. All SELF accounts share a well-known security identifier (SID) that is the same across all domains. If the SELF account is not already listed in thePermissions dialog box, you can add it by typing SELF as the account name. Only one account at a time can have the Associated External Account permission. If this permission is currently owned by an account that is unwanted or that is not valid, you must remove the permission on that account before you apply the account to SELF. After you remove the Associated External Account permission from an account, exit all properties dialog boxes for the disabled user object. (To do this, click OK, not Cancel, at each level.) You must do this because changes to permissions are not applied immediately, but only after you have exited the object properties for the user. You will be blocked from changing the owner of the Associated External Account permission until you have closed and re-opened the properties of the object. Reset the Associated External Account permission to SELF. You can use LDAP tools, such as the Active Directory Service Interfaces (ADSI) Edit snap-in, the LDP utility or Ldifde to view the attributes of the user object to verify that the msExchMasterAccountSID attribute has been created. Because of directory replication and Exchange Server cache refresh latencies, it can take up to two hours after you make the change before the mailbox can be moved. To set the msExchMasterAccountSID attribute for lots of disabled user accounts, you can use the Collaboration Data Objects for Exchange Management (CDOEXM) interface to modify the mailbox security descriptor. Starting with Microsoft Exchange 2000 Server Service Pack 2 (SP2), a new interface is made available in CDOEXM. This interface is named MailboxRights. This exposure lets you modify the mailbox security descriptor programmatically. For more information about how to script a bulk change of the msExchMasterAccountSid attribute, click the following article number to view the article in the Microsoft Knowledge Base: 322890  How to associate an external account with an existing Exchange 2000 mailbox For additional methods that let you set the msExchMasterAccountSid attribute for lots of disabled user accounts, contact Microsoft Product Support Services. For more information about the support options that are available from Microsoft, visit the following Microsoft Web site: http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS To determine how many disabled user accounts do not have the msExchMasterAccountSid attribute, you can generate an LDIF formatting export file. To do this, run the following Ldifde.exe command: ldifde -f file.txt -d "dc=domain,dc=com" -l nothing -r "(&(objectcategory=person)(objectclass=user)(msexchuseraccountcontrol=2)(!(msexchmasteraccountsid=*)))" The following list describes the Ldifde parameters: -f: This switch indicates the export destination file. -d: This switch indicates that the Microsoft Windows domain from which to export user objects. For example, if the Active Directory Users and Computers management console for the domain lists the domain ascorp.company.com, it would become "dc=corp,dc=company,dc=com". -l: This switch, if it is used, restricts output to the export file of only the attributes enumerated by the switch. In this case, the non-existent attribute nothing is used so that only object names, not attributes, are generated. -r: This switch indicates the LDAP search filter by using the standard LDAP query syntax. You can also use this search string with Ldp.exe and other LDAP tools. In this case, the search is for all user objects that are disabled (msExchMasterAccountControl value of 2) and that do not have an msExchMasterAccountSIDattribute. The following text is an example of the output file: dn: CN=AAA R1,OU=Recipients,DC=domain,DC=com changetype: add dn: CN=AAA R2,OU=Recipients,DC=domain,DC=com changetype: add . . . . . For more information about how to use Ldifde in Active Directory, click the following article number to view the article in the Microsoft Knowledge Base: 237677  Using LDIFDE to import and export directory objects to Active Directory Note We do not recommend that you use the LDIFDE command-line utility or the ADSIEDIT tool to create, to modify, or to delete the msExchMasterAccountSid attribute.