Some correspondents have kolab_user at kolab_server instead of From address in their replies

[Johannes Ranke]

Hi Lennart,

thanks for sharing your suggestions! In order to check if SPF and DKIM are 
aligned with the envelope from, I have now added a DMARC entry with an e-mail 
address for reporting to my DNS, so I should start receiving reports about any 
problems.

Kind regards,

Johannes

Am Montag, 3. Januar 2022, 15:00:15 CET schrieb Lennart:
> Hi Johannes,
> 
> My hunch is that kolab.jrwb.de is set by Postfix as the envelope from
> (aka SMTP FROM aka Return-Path, as opposed to the From header in the
> message itself). The Sender header may be added either by Postfix or an
> intermediate SMTP server to indicate the original envelope from.
> 
> My envelope froms are also different from From headers and I'm not aware
> of any problems. My only advice would be to have the top domain part
> (i.e. jrwb.de) identical to the From header (to appease spam filters)
> and to make sure that SPF records are set for the envelope from domain.
> It's also important that emails to the envelope from address are
> deliverable, since it is where bounces are sent.
> 
> Hence, in deciding whether to use different envelope from addresses, I
> think your primary concerns are: (a) are the SPF records set up
> correctly for all domains that will be used as envelope from? (b) Where
> do you want bounce emails to be delivered to?
> 
> Best,
> 
> Lennart
> 
> On 08-12-2021 09:16, Johannes Ranke wrote:
> > ...
> > 
> > > This leaves me wondering if the Sender: should not be set to my
> > 
> > primary e-
> > 
> > > mail, and if yes, how I could achieve this.
> > 
> > I found some discussion on Stackoverflow on this [1], leading to RFC
> > 4021, updated by RFC 5322 [2]. All the RFCs which I looked up say that
> > a Sender: header should only be included if the author of the message
> > and the transmitter are not identical.
> > 
> > 
> > So should I tell postfix not to include a Sender: address, and if yes,
> > how? I have no delegates specified in the kolab-webadmin, and none of
> > my users need this functionality.
> > 
> > 
> > Johannes
> > 
> > 
> > 
> > [1]
> > https://stackoverflow.com/questions/4367358/whats-the-difference-between-s
> > ender-from-and-return-path
> > <https://stackoverflow.com/questions/4367358/whats-the-difference-between
> > -sender-from-and-return-path>
> > 
> > 
> > [2] https://datatracker.ietf.org/doc/html/rfc5322#section-3.6.2
> > <https://datatracker.ietf.org/doc/html/rfc5322#section-3.6.2>
> > 
> > 
> > _______________________________________________
> > users mailing list
> > users at lists.kolab.org
> > https://lists.kolab.org/mailman/listinfo/users


-- 
Johannes Ranke
Wissenschaftlicher Berater
07624 8099027
https://jrwb.de