[Mailman-Developers] Re: Cutting "Received:" headers

[Tom Neff]

--On Friday, June 13, 2003 5:32 PM -0400 Barry Warsaw <barry at python.org>
wrote:
> The other case can be made that retaining Received headers has very
> practical benefits.  For example, it occasionally happens that a piece
> spam sneaks through our filters (I /know/!  Imagine that. ;).  Then
> python.org gets blamed for spamming people.  Having the Received headers
> in there has so far proved that the spam did not originate from us.

Hey, I completely agree that keeping Received: can be very useful, and for my
own lists I would probably not select "clean_headers" if it were implemented.
But I can see where some people might prefer it, and I don't agree that it is
somehow "RFC forbidden" to do such a thing: listservs are not SMTP relays or
gateways in the sense of the term used by RFC2821-2.  That was the point of
my posting.

>> I would be in favor of a "clean_headers" per-list option which, if True,
>> would remove all but a minimal, rational set of headers from messages
>> before they are reposted.
> 
> Which headers should be removed?  I guess you'd need a general mechanism
> to clean out any header.  Personally, I don't think the Received headers
> are any problem.

It would be more like "which headers are retained."  I would suggest From,
To, Subject, Reply-To, Message-Id, In-Reply-To, and of course Content-Type
and other MIME headers as appropriate.  Everything else, including old Spam
scores, X-Nostradamus-Lives headers, stale Receiveds, etc, etc, would be
gone.  Of course you could embed an exact "retain list" somewhere in
mm_cfg.py if you wanted, so that tinkerers could add or remove headers to fit
their sites' needs.

>> In the meantime, any site admin who wants to do this kind of cleaning can
>> easily insert "formail" or "reformail" into the alias pipeline for the
>> posting address.  These are utilities supplied with "procmail" and
>> "maildrop" respectively, and widely available on the Net.
> 
> And of course, it would be easy to edit Cleanse.py or add a new, fancier
> handler module in the standard Mailman pipeline to get rid of these
> headers.

Yeah, but that's a lot more forking for a little bit of work...