The Mail Delivery (POP3) monitor works by connecting to a POP3 service and checking to see that it is responding. There are no settings necessary for this monitor.
Note: Mail Delivery (POP3) services are completely separate from Mail Transfer (SMTP) services, even if in some cases they can be run by the same program. For complete checking of your mail system, you should use both types of monitors on your mail server.
The Mail Delivery (POP3) monitor first initiates a connection to the service and waits for a "+OK" response.
If the monitor receives the "+OK" response, the test is successful.
If the monitor receives a "-ERR" response, the test will fail with an error.
Otherwise the monitor will continue to wait. If the desired response is never received, the test will fail with a timeout error.