[Mailman-Users] Newsgroup interface and registration

[David Beaumont]

Our usenet newsgroup 'annexcafe' have started requiring registration, to
prevent spamming of the newsgroup.  However since they did this the
interface with out mailman list has stopped working both ways.  Emails no
longer get posted to the newsgroup and newsgroup postings no longer get sent
out as emails.  

The newsgroup now requires users to log in with their username and password,
but there is no option to put login details into mailman that I can find.
We have mailman v 2.1.8

Has any had this problem and got round it?  Or anyone know of newsgroup
providers that don't require login?  Or of any software that does emails,
web based forums and newsgroups in one?

Thanks

David