The Mail Service Layer
The Mail test associated with this layer, emulates a mail send-receive activity on the cluster to determine its availability and responsiveness. The test sends the emulated request to the virtual cluster server (i.e., the Exchange Cluster), which will promptly forward the request to that node in the cluster that currently owns the cluster server. If at least one node in the cluster is currently active, then the mail will be successfully sent/received, indicating the good health of the cluster. On the other hand, if none of the nodes in the cluster are active, then the emulated request will fail, indicating the non-availability of the cluster.
Figure 2 : Tests mapping to the Mail Service layer