I'm running PRTG 18.104.22.16804, and setup the POP3 Roundtrip sensor. However, its status always shows down with the messages "Maximum Trip Time exceeded (giveing up)" or "Unexpected connection drop (code: PE039)".
I've also add the SMTP and POP3 sensor to the same server and both are running normally (response time around 2-3 msec).
The probe and the mail server are on the same local network, so there should not be affected by the network condition. Anyone have idea on that issue?
Thanks in advance.