Why would you want to post mailing list traffic to local news groups?
Should more than one user subscribe to the same mailing list, there is going to be traffic duplication. By subscribing the site to a list (if this is allowed by the list owner) and 'gating' the email traffic to the local news server, it is possible to make mailing lists accessible to all site users, or, using the security features of 'innd', to limit the access to certain users. Such a site subscription (particularly if there are a number of high traffic lists) can make worthwhile savings in bandwidth usage.
Also, reading list traffic via a newsreader offers the advantages of threading and scoring/killfiles which tend not to be available in all mailreaders. And, of course, it keeps your inbox free free for possibly more urgent, personal email.
This mini-HOWTO describes setting up the 'mail2news' script to accomplish this.
You can download the mail2news package including the script and this HOWTO and other documentation from