Let's imagine such experiment:
1. we have java-program, which receives mail from some POP3 server.
this program simple uses something like this:
....
msgs = folder.getMessages(1,1);
folder.fetch(msgs, fp);
....
2. Let's imagine, that our test POP3 server has bug: in some moment, when our java-mail-client sends him command "RETR" or "TOP", mail-server becomes non-repsonsible, I mean it begins do something, like this:
do {
if (Thread.interrupted()) break;
} while (true);
So, the problem is, that in this case our javamail client becomes also
non-responsible, non-interruptable and so on.
Researches show, that problem is in native java-method: socketRead0 (in class SocketInputStream), which is blocking, non-interruptable method. This method is used by javamail classes for operate with sockets.