On Sat, Jul 14, 2012 at 06:23:22PM +0530, achal tomar wrote:
> actually Viktor this signed by: header requires DKIM authentication so when
> mails are sent from many servers on the same domain then their signatures
> are different but having the same signed by: header means that they are
> authenticated from a single domain and this do not requires dkim to be set
> up in all the servers entry in a single server is enough.
>
I see no mention of a "Signed-By:" header in the DKIM RFC. DKIM
specifies a "DKIM-Signature" header field:
https://tools.ietf.org/html/rfc4871
If this is what you mean by "Signed-By", then sure, use DKIM to
sign your mail. DKIM signatures require the signing hosts to have
access to an RSA private key associated with the signing domain.
Multiple keys can be associated with the same domain via a "selector".
Postfix supports DKIM signing either via a milter or a content-filter
such as amavisd-new.
--
Viktor.
