How to use Gmane

Hi,
I can't see how gmane would work to deal with mailing lists.
I would much rather use the usenet interface to mailing lists than 
actual mail, but...
If I post a reply to a post via NNTP, then does the gmane server send a 
mail posting my reply to the list via email? Is that how it is supposed 
to happen?
If so, how can gmane bypass spf?