PopMan

Popman suddenly stop working: Invalid server response; ErrCode:502
Outlook and another email notification program works fine.

Can you provide a bit more information, please?!

What email provider do you use (POP3 server)?
What email protocol do you use for this account (POP3, POP3 SSL, IMAP)?
Please verify that all of your account setting are correct, especially pop3 server, user name, password.
Do you use a firewall or anti-virus program, that might block PopMan from accessing the internet? A firewall keeps track of all applications that are allowed to access the internet and may suddenly block a certain application, if its program exe file has changed (e.g. after updating PopMan to a new version)...

1. pop3 server
2. pop3 protocol
3. all of setings are correct
4. Yes, using Tiny PF and NOD32 antivirus but same problem occurs even if I shut down both of them

Problem persists with three popman versions: 1.2.1, 1.2.2 and 1.3 beta.

1. pop3 server

The question was: What pop3 server do you use?

Sorry.

pop3.beotel.yu

I found that Popman works fine with other server. It seems that it is problem with pop3.beotel.yu server. But what happened? Everything worked well till today and everything works well with other email notification program?

Do you check other email accounts with PopMan successfully? I still think, that a sudden PopMan specific connection problem is an indicator of firewall misconfiguration (PopMan.exe is changed due to an update, therefore the firewall thinks PopMan.exe must be blocked from now on).
But if you can use other accounts successfully, the firewall theory is disproved.

Maybe you send me the log file "PopManLogFile.log". You can find the location of this file on the "Logging" tab of the options dialog...