Kmail: does not warn if POP3 server closed

"As to the closed 110, it means that I have not started the service! (though kmail does not warn about it: reproduce: close port 110 on mail server, connect to it with kmail and it will pretend to "download" happily from it!" ([Local#4331-22])

Kmail does not indicate that a server might be down, that the POP3 service is not enabled, etc. Trying to download emails from such a server will cause kmail to pretent to successfully connect and download 0 emails. There is no indication that anything is amiss.