appliance has one built-in monitor that can be used to monitor SMTP services:
SMTP monitor. It periodically checks the SMTP
service to which it is bound by opening a connection with it and conducting a
series of handshakes to ensure that the server is operating correctly. If the
SMTP service completes the handshakes properly, the monitor marks the service
UP. If the SMTP service does not respond, or responds incorrectly, it marks the
Note: Monitor probes originate from the NetScaler IP (NSIP) address.