From: Rich Salz <rsalz@nntp.com>
Date: Thu, 14 Sep 95 07:31:06 PDT
To: Remailer-Operators@c2.org
Subject: Re: Mixmaster posting poll
Message-ID: <199509141429.KAA23068@nntp.com>
MIME-Version: 1.0
Content-Type: text/plain


> I think that I am not being clear enough about what I want to do.

Ah, now I understand -- thanks for the clarification.

Let me waste a bit of time on some general news/mail issues.  The two
formats are very similar, but not identical.  This is generally a good
thing.  For example, it's easy to write a single user interface that handles
both.  (Many people like having killfiles on their email, for example.)

However, when you start to gateway between the two, the differences become
more important.  For example, suppose an article has To, Newsgroups, and Cc
headers.  What should happen?  Some news user-agents (used to?) email as
well as post when given a news article with those headers.  And what happens
when an article is then gatewayed back out to email, and care isn't taken to
strip those headers off?  (Rhetorical question; I don't know.)  I think
this is of particular concern to this community.  Imagine a mail->news remailer
that gatewayed messages by connection to UUNET's accept-from-anyone server
and posted them to alt.blacknet.  Interested parties might then get a full
feed and locally gateway alt.blacknet into a mailing list.  So this kind of
multi-time gatewaying, if not common now, could (and should?) be soon.

I guess that's a long way of saying "be careful." :)

The advantage of using "news.group@gateway.host" is that it might
avoid these confusions since the Newsgroup header appears out-of-band.
However setting up gateways like this is often harder, requiring
special prefixes (viz., usenet.news.group@gate.host is/was common)
hundreds (thousands) of aliases, or the ability to set up special
mailer config (typically sendmail.cf on the internet these days)
that recognize only the top-level hierarchies (of which there are
hundreds, changing weekly).  There is also the problem of making sure
that the mail newsgroup list is kept in sync with the local host's
newsgroup list.  An even bigger problem is that cross-postings are
essentially impossible (you get multiple copies); this can be annoying
if you want to cross-post to a group that the gateway host doesn't receive.
A workable trick is to post to control,alt.blacknet -- everyone "gets"
control but only those that care will see the article where it should
really go.

If you use something like mail2news@gate.host, then the newsgroups are
in the Newsgroups header.  You have to be careful about To and Cc but
you don't have the problems mentioned above.

I think the header problem is more likely fixed/fixable, and therefore suggest
the second syntax.

If you do local gatewaying, you should really send your article into rnews
and not inews.  Inews will mess with headers, which is okay for users or
scripts that know they can be sloppy.  But not okay for gateways which
don't want .signature files appended, too-much-quoted-text counted, etc.
Feeding into rnews is not difficult -- you need merely ensure that your
message has these six headers:  Message-ID Newsgroups From Date Subject Path.
The other advantage of feeding into rnews is that rnews always spools if
the news processor is unavailable, while inews doesn't.

Another option is to provide a program that can connect to a specified
host and inject the gatewayed article directly using the NNTP protocol.
This is not hard; INN includes a program (feedone.c) that does it in
about 200 commented source lines.

INN is available from many places, including
	ftp://ftp.uu.net/networking/news/nntp/inn/inn1.4sec2.tar.Z
and my news/mail gateway software (newsgate) is available by sending
me email.

Hope this helps.
	/r$
>
> At 8:35 AM 9/13/95, Rich Salz wrote:
> >>       If the form alt.usenet.group@remailer.com was used, wouldn't the
> >> system running the remailer have to have an alias defined for each and
> >> every newsgroup that it plans on handling?
> >
> >No.  Sites running sendmail, for example, could set up rules that
> >just knew the top-level hierarchies and fed those into a special
> >"mailer" that gatewayed them.
> >
> >My opinion is that making any names well-known is a bad idea, and
> >that attaching special semantics to "mail2news@xxx" is a real bad
> >idea.  Instead, just send the message to the specified recipient
> >and let do whatever magic needs to be done.
> >
> >If mixmaster wants to function as a mail/news gateway, it should
> >do something special when it sees the Newsgroups header -- process
> >the message and feed it into rnews, presumably.
> >
> >I guess, but not yet having read the code do not know, that this is
> >cleaner and more easily extensible (or removable).
> >        /r$
>
> ----------------------------------------------------------
> Lance Cottrell   loki@obscura.com
> PGP 2.6 key available by finger or server.
> Mixmaster, the next generation remailer, is now available!
> http://obscura.com/~loki/Welcome.html or FTP to obscura.com
>
> "Love is a snowmobile racing across the tundra.  Suddenly
> it flips over, pinning you underneath.  At night the ice
> weasels come."
>                         --Nietzsche
> ----------------------------------------------------------
>
>
>