> POP/IMAP are for reading email from the receiving server, not for sending out new emails.
They probably shouldn't be, though, there's an IMAP extension for submission.
> I was under the impression that most Usenet networks used UUCP.
No, NNTP. UUCP hasn't been used seriously for over a decade.
Yours, news.ycombinator.com!ethomson