About your original question:
From your message I deduce that the message-id is added by your client
in the first place? In that case, no, I don't think OpenSMTPd can be
told to basically *replace* the message id for you.
That said, OpenSMTPd as a standard compliant mail server will add or
replace a message-id, *iff*:
- this is a submission on port 587
- and if it is missing or an incorrect (syntax) one
This is specified in [0] (RFC6409) under 8.3.
In that very case, I think the "hostname" setting of the "listen"
directive will be used for the message-id (the handling is around line
2750 in smtp_session.c), but might be wrong, haven't tested that. Either
way, this wouldn't help you, I think.
Also note that the MSA adding a missing message-id is only to ensure
compliance with standards for other MTAs, though, b/c there are too many
broken clients out there that don't add one to begin with. This byself
isn't ideal actually (e.g. they give examples in that RFC under 8, like
if this is added later on, it might mess with the validity of message
signatures).
Long story short, IMHO:
- make sure your client adds such a header
- make sure that the client adds it in the format you want
Overall, I don't think that the content of the message-id header is used
for spam detection... but who knows, mailer corps do all kinds of weird
stuff...
... and speaking off weird stuff, about Leo's argument about t-online:
what he writes is actually documented as-is by t-online's guide for
server operators [1]. They say the "mail" in the hostname is
"recommended", however, the part about the website with imprint sounds
like a requirement, under 4.1 of [1]:
"In particular, we recommend choosing a host name that indicates its
usage as a mail server (eg. mail.example.com) and to ensure the host's
domain leads to a website providing full contact details."
I personally think this is messed up and agree with Leo here. But then
again, the big mailers do whatever they want anyways, and always make it
harder for the small and private ones, in one way or another, for the
sake of whatever they claim. Anyone surprised here?
[0] https://datatracker.ietf.org/doc/html/rfc6409
[1] https://postmaster.t-online.de/index.en.html
On Wed, Nov 03, 2021 at 06:14:20PM +0000, Manfred Lotz wrote:
On Wed, 3 Nov 2021 14:59:15 +0100
Leo Unglaub <l...@unglaub.at> wrote:
Hey,
i am not sure if that is directly related to you problem, but
t-online.de is one of the worst email providers i have ever seen.
They eandomly block you for no reason. Last month i got bocked
because the hostname of my email server did not contain the word
"mail". They demandet that all of the sudden. Then they only accepted
emails from my servers if on the same IP as the mailserver there was
a websever that served a valid impress/legal notce. Totally nuts that
t-online.de company.
I have no problem with t-online.
