On 14.09.23 13:08, Marc Lucke via Postfix-users wrote:
re:
https://techcommunity.microsoft.com/t5/exchange-team-blog/updated-requirements-for-smtp-relay-through-exchange-online/ba-p/3851357
Let's say I send an email. I use:
mail from: <annoy...@spammer.com>
and in the data (body)
From: Professional Legit Person
<igotalovelybunchofcoconuts@innocent.pizza>
Looking at headers from Microsoft, they track 2 fields: smtp.mailfrom
and header.from
From what I can work out, they'll start to say that if smtp.mailfrom
!= header.from (in my example, spammer.com != innocent.pizza),
Microsoft will bounce the email - even if authenticated etc. They
seem very happy to spend our time, huh? (unless I have something
wrong)
I don't think so. Many mail resenders e.g. mailing lists change envelope
from: and keep header From:
what they are removing, is the check of correct header From: and you must
provide correct certificate or correct envelope from: for mail to be
accepted.
I can & do use generic sender address masking successfully. In fact,
in the above example, in reality, "innocent.pizza" is actually the
hostname in most cases. generic is the wrong solution to my issue.
Also masquerading won't work, because I can't guarantee who the "mail
from: " that postfix includes will be.
I don't agree with Microsoft's action here, & think many use cases
would be broken if everyone did this, such as my forward from yahoo, &
maybe mailing lists.
My question is this: is there a way to hide the "mail from: " value
No. The envelope (mail from:) sender is used in SMTP protocol and most of
postfix checks.
from Microsoft & instead use the generic mapped sender instead? In my
example, Microsoft would only ever see "innocent.pizza" and never
"spammer.com" as if I'd originally done this instead, when I did not:
mail from: <igotalovelybunchofcoconuts@innocent.pizza>
Why do you accept mail from incorrect (spammer) envelope domain?
Why not fix this problem in the right place (sender)?
--
Matus UHLAR - fantomas, uh...@fantomas.sk ; http://www.fantomas.sk/
Warning: I wish NOT to receive e-mail advertising to this address.
Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu.
Atheism is a non-prophet organization.
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