Use ADModify.NET to Fix System Attendant Mail Flow Problems

Exchange 2007

Microsoft Exchange Server 2007 will reach end of support on April 11, 2017. To stay supported, you will need to upgrade. For more information, see Resources to help you upgrade your Office 2007 servers and clients.


Topic Last Modified: 2016-11-10

This topic explains how to use the ADModify.NET tool from CodePlex to modify user ExchangeLegacyDN attributes. You can do this to resolve problems that affect Free/Busy data and System Attendant mail flow.

When you moved all the users from an earlier version of Microsoft Exchange to Microsoft Exchange Server 2007, you may also have removed the original Exchange Server 2003 or Exchange 2000 Server Administrative groups.

Microsoft recommends against removing the original Administrative groups from an Exchange organization.

If any of the original Exchange 2003 or Exchange 2000 Administrative groups were removed, you may experience all the following symptoms:

  • Mail may build up in the System Attendant mailbox on Exchange 2007 servers.

  • Free/Busy information may not be updated correctly for Microsoft Office Outlook 2007 or for earlier Outlook clients.

    These clients store Free/Busy information in public folders.
  • If you have storage limits that are configured to disable mailboxes when a particular storage limit is reached, the following event may be logged on Hub Transport servers:


    Event ID: 1022

    Category: None

    Source: MSExchangeIS Mailbox Store

    Type: Error

    Description: Logon Failure on database "<database_name>" - Windows account Contoso\<ServerName>$; mailbox /o=ContosoOrganization/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Configuration/cn=Servers/cn=<ServerName>/cn=Microsoft System Attendant

    Error: 1245

This issue occurs when the ExchangeLegacyDN attributes of the affected user accounts point to a deleted Administrative group. In this scenario, you must update the ExchangeLegacyDN attribute for each affected user. The ExchangeLegacyDN attribute must be updated to the following conditions:

  • The attribute must be converted to an X500 address type. Each user must have a unique X500 address.

  • The attribute must be updated to use a unique ExchangeLegacyDN attribute as appropriate for the Administrative group in which the user account is located.

You can use a bulk modification tool, such as LDIFDE or ADModify.NET to perform this operation. For detailed instructions about how to modify the ExchangeLegacyDN attribute, see step 5 under "To remove the last Exchange 2003 or Exchange 2000 server from an Exchange 2007 organization" in How to Remove the Last Legacy Exchange Server from an Organization.

For more information about how to use ADModify.NET, see the following Microsoft Web log (blog): ADModify.NET is here.

The content of each blog and its URL are subject to change without notice.