It is probably your server mailbox that needs cleaning out.
A further explanation is needed to help you with this one. What happens
when you receive these messages? Is there an error message or does Eudora
crash when attempting to download them or what? Is it possible that the
problem is that you've told Eudora to skip messages over a certain size,
and these messages are over that size, causing them to be skipped? If
that is what is happening, you should be getting message stubs that
contain the headers and maybe a few lines of the body of the message.
YOu need to then decide whether you want to download the full messages
or not and tell Eudora what to do with them. (There are buttons to do
that in the open messages (not in the preview pane) or you can use
"change server status to do it.) If Eudora can't download them, or isn't
set to do so, and they're being left on the server, that might explain why
your server mailbox is so full. Some pdf files are quite large.