> I'am using QPopper 4.03 > Some of my pop-users receive messages like this one:
That's actually a Pine thing. Pine 4.x generates those messages, but you can only see them when using other mailers, or popping your box. Two ways to fix it: 1) Set the option "quell-internal-folder-msg" to yes in your site-wide pine.conf; or 2) recompile qpopper with the --enable-uw-kludge in the configure.
