[Mailman-Users] sender/envelope addresses esp with mailed commands

Tony Abbott tabbott at intekom.com
Mon Jul 19 11:38:53 CEST 1999

Nigel is having the same problem I had - the Sender: header exists, but
is unqualified. This is the way that Netscape Communicator (at least the
Unix version) generates the header and as such is something we have to
deal with. I worked around this by modifying GetSender to use Reply-to:
if available or else From:


"Barry A. Warsaw" wrote:
> >>>>> "NM" == Nigel Metheringham <Nigel.Metheringham at vdata.co.uk> writes:
>     NM> I am using Mailman 1.0rc3 (same result with 1.0rc2).  I have
>     NM> the default zero setting for USE_ENVELOPE_SENDER.  The MUA I
>     NM> am using on the test account is Netscape running on Linux
>     NM> connecting through an ISP by POP/SMTP.  Netscape appears to
>     NM> add a "Sender: nigel" header - ie my unqualified user name,
>     NM> which is not qualified by any of the MTAs on the way
>     NM> (basically none of the MTAs will have sufficient information
>     NM> to qualify it so they shouldn't be playing with it).
>     NM> Fixing up the sender header is not really an option - it
>     NM> impacts to many other peoples systems.
>     NM> I tried just stripping the sender header (assuming that would
>     NM> cause a drop back to From: headers as is implied in the FAQ
>     NM> etc), and managed to completely break list posting :-(
> I don't understand this part.  Where did you strip the Sender: header?
> Look at IncomingMessages.GetSender() in Mailman/Message.py.  It
> definitely falls back to using From: if Sender: doesn't exist.
>     NM> So I guess that Mailman, to be safe, should check the sender
>     NM> address more carefully - specifically if it is not qualified
>     NM> then it should discard it and use the From: or envelope (maybe
>     NM> Return-Path:) address in its place.
> Mailman /could/ have some cascading algorithm for authenticating an
> email address (i.e. authenticate Sender -> From -> Reply-to ->
> Envelope Sender).  That's a big change to the current situation, so
> I'm not going to do this for the 1.0 release.  Mailman currently only
> authenticates the first address it finds and if that fails then the
> message gets held.
> However, if your ISP is inserting an unqualified Sender: address into
> outgoing mail it is broken.  You say fixing this is not really an
> option, though I don't understand why that is (it what way does it
> impact many other people's systems?).  If that's really the case I
> don't know what you can really do.
> -Barry
> ------------------------------------------------------
> Mailman-Users maillist  -  Mailman-Users at python.org
> http://www.python.org/mailman/listinfo/mailman-users


    Tony Abbott					tabbott at intekom.co.za
    Systems Administrator, Intekom		Tel: +27-11-266-7800
    http://www.intekom.co.za			Fax: +27-11-315-0707

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