Delete mail: if ticked, retrieved messages will be deleted from the server when they are deleted from the Trash folder.
Skip large e-mails: if ticked, large e-mails will be left on the server. You can retrieve the large messages by choosing Get this mail from the Retrieve mail dialog.
Synchronize with server: most users should have this option ticked. When ticked the email client remembers the list of mails on the POP server.
Base folder: if your mail folder is not your root folder you can set the base folder here (e.g. Inbox).
See Also: Internet Help