KBiff is a KDE "biff" or new mail notification utility. It is highly configurable but very easy to use and setup. It supports session managment (it "remembers" the last state it was in before you logged off) and can be docked into the panel. It has support for mbox (Unix-style), maildir (qmail-style), mh, POP3, IMAP4, and NNTP mailboxes.
