If you have a firewall present on your network, it can blocking connections from DNS Made Easy Failover/System Monitoring servers. Since they aggressively monitor these any systems (usually once every 100 seconds or less) set up with this service, many firewalls can often start to block our connections since it might look like an attack of some sort. This can be done both by the sever itself (web server, application server, etc..) or by an external firewall or a IDS / IPS.
Here are the current networks that you will see us monitoring from:
So it Dnsmadeeasy Failover not working, please whitelist the above ipaddresses in firewall.