The mailing list for listmasters using Sympa

[Serge Aumont <address@concealed>]

 Le 05/11/10 13:46, Niklas Matthies a écrit :
> Another comment: Apparently the Sender header is being added for DKIM
> compatibility. But I couldn't find anything in the DKIM specs that
> would suggest that it is required. (I'm not really familiar with DKIM
> though.) In any case, maybe it could be restricted to when dkim_feature
> is set to "on".
You are right: we decided to add this header when discussing DKIM and 
mailing list with DKIM gurus.

The way mailing list must use DKIM is still not very clear because 
mailing list servers usually modify messages in a way that existing DKIM 
signature are broken. So the mailing list server should add its own 
signature. This signature may not be compatible with the original Sender 
DKIM  policy, so the final MTA should check the signature policy of the 
real Sender of the message which is the mailing server.

Mailing list servers, especially Sympa are not remailers  : they are the 
Sender: because they modify an existing message before to distribute  It 
is a pretty good usage for a mailing list server to add a Sender: header 
because the semantic of this header is to spécify which agent did 
introduce the message in the SMTP network.

Anyhow : you can remove this header by configuration of parameter 
"remove_outgoing_headers"  : list admin / edit list config / sending 
receiving / remove_outgoing_headers

We are using this header for a long time now on our own server with or 
without DKIM signature and without any trouble.

Serge Aumont