Topic Last Modified: 2007-01-17

The Microsoft® Exchange Server Analyzer Tool queries the Active Directory® directory service to determine the number of connectors that are present in a given routing group, including SMTP connectors, routing group connectors, X.400 connectors, and EDK connectors. If the Exchange Server Analyzer finds more than 900 total connectors in any single routing group, a warning is displayed.

It is recommended that you use a maximum of 900 instances for any single Exchange object type. This is because Active Directory defaults to 1,000 as the maximum page size that it returns for any given request. This means that if a Lightweight Directory Access Protocol (LDAP) request is made for an object, and more than 1,000 instances of that object exist in Active Directory, no results will be returned because the maximum page size is exceeded.

In the case of Exchange Server, various processes request instantiation of specific object types. For example, Exchange System Manager makes an LDAP request to Active Directory to create a list view of all connectors within a routing group. If there are more than 1,000 connectors in any single routing group, Active Directory will not return any query results. When this happens, an error is displayed in Exchange System Manager.

Although the maximum page size value for Active Directory can be increased, this is not recommended or supported for Exchange Server. Odd behavior and failures have been exposed in Exchange environments where the maximum page size value has been increased.

Although the recommendation is to remain at or below 900 for any single object type in Exchange Server, up to 1,000 object types are supported.

To correct this warning

  1. Consider consolidating connectors or creating more routing groups and load balancing the existing connectors among them.

  2. Examine Active Directory for orphaned connectors and remove them from Active Directory.

  3. Consider consolidating Exchange servers in your organization.

For information about routing group design and connectors, see the Exchange Server 2003 Transport and Routing Guide (

For more information about consolidating Exchange servers, see Server Consolidation Using Exchange Server 2003 (