Check to make sure that the ENow Admin and ENow Client services are running on the monitored server.  In addition, make sure that the MailscapeAgent.config file located on the monitored server is pointing to the FQDN or IP address of the EMS web server.  The actual test performed involves transmission of the \Program Files (x86)\ENow\Mailscape Agent\Heartbeat.xml file from the monitored server to the web server.