News server(NNTP library) and Python

[Lad]

I have a program that can send posts to a news server.The problem is
that I must find a free usenet(news) server that allows posting, which
is not easy. For this reason I would like to make a modification in my
program so that the program can act in a similar way how real news
server, that is to spread the new posts to another news server. But I
do not have much knowledge about the way how news server chooses
another news server to send it's new posting.
Can anybody give me a hint( idea)?
Thanks
Lad