There is only one MTA resource per Exchange 2000 Server cluster or Exchange Server 2003 cluster

When you install Microsoft Exchange 2000 Server or Microsoft Exchange Server 2003 on a Microsoft Windows 2000-based cluster, there is only one Message Transfer Agent (MTA) resource per cluster.

This behavior is by design. The MTA resource is not cluster-aware. There is one MTA resource per cluster.

The MTA is an Active/Passive cluster resource. There can only be one MTA per cluster. On Active/Active clusters, only one virtual Exchange server will have the MTA resource. The MTA is created on the first Exchange virtual server and serves all Exchange virtual servers in the cluster.
For additional information about how to implement Exchange 2000 Server on a Windows 2000-based cluster, click the following article numbers to view the articles in the Microsoft Knowledge Base: For additional information about Exchange 2000 Server components that are supported in a clustered environment, click the following article number to view the article in the Microsoft Knowledge Base: For additional information about installing the Windows 2000 Cluster service, click the following article number to view the article in the Microsoft Knowledge Base: