How to Remove Exchange SRS
Site Replication Service (SRS) is a component that exchanges configuration information between Active Directory and the directory in Exchange 5.5. You cannot switch to native mode until you have removed all instances of SRS.
To remove Exchange SRS
From the Active Directory Connector Tool MMC snap-in, navigate to your recipient connection agreements. To remove any recipient connection agreements that exist in your Exchange organization, right-click the connection agreement, and then click Delete. You should also remove any public folder connection agreements.
Either from another Exchange 5.5 server, or directly from the Exchange 2003 server that is running SRS, open the Exchange 5.5 Administrator program. This is typically the first Exchange 2003 server installed in an Exchange 5.5 site. Click File, click Connect to Server, and then type the name of the Exchange 2003 server running SRS.
In the Exchange 5.5 Administrator program, expand the local site name (displayed in bold), expand Configuration, click Directory Replication Connectors, and then delete any directory replication connectors that exist.
Do not delete the ADNAutoDRC connector listed under Directory Replication Connectors.
Allow time for the changes that you made in Exchange Administrator to replicate to the configuration connection agreements (Config CAs) to Active Directory.
In Exchange System Manager, ensure that no Exchange 5.5 computers are displayed in any administrative groups.
In Exchange System Manager, expand Tools, and click Site Replication Services. From the details pane right-click each SRS, and then click Delete. When you do so, the SRS and corresponding Config CA for that SRS are deleted.
After all instances of SRS are deleted, use the Services MMC console to stop and disable the Site Replication Service and the Active Directory Connector (ADC) service.
For More Information
For more information, see "Planning to Move from Exchange 5.5 to Exchange 2003" in Planning an Exchange Server 2003 Messaging System.