Dominic Raferd:
> On Wed, 8 Aug 2018 at 11:50, Wietse Venema <wie...@porcupine.org> wrote:
>
> > Dominic Raferd:
> > > canonical:
> > > <> root
> >
> > I don't know of any promise that canonical_maps will use <> as the
> > lookup key for the null address.
> >
>
> I will remove that, I put it there a long time ago when I knew (even) less
> about postfix. But I doubt it is the cause of my problem here?
If you're referring to envelope.from versus header.from alignment
of bounce messages, then you may want to read RFC 7489 section
3.1.2. which in turn refers to RFC 7208 Section 2.4 which, says:
[RFC5321] allows the reverse-path to be null (see Section 4.5.5 in
[RFC5321]). In this case, there is no explicit sender mailbox, and
such a message can be assumed to be a notification message from the
mail system itself. WHEN THE REVERSE-PATH IS NULL, THIS DOCUMENT
DEFINES THE "MAIL FROM" IDENTITY TO BE THE MAILBOX COMPOSED OF THE
LOCAL-PART "POSTMASTER" AND THE "HELO" IDENTITY (WHICH MIGHT OR MIGHT
NOT HAVE BEEN CHECKED SEPARATELY BEFORE).
(emphasis added by myself).
Thus, if you are concerned that your bounces are failing alignment
checks, then do not change the null address, instead, adjust your
HELO domain name such that it is aligned with the header.from.
Never have I expected that I would have to explain how to use SPF.
Wietse
