On 01/27/2018 12:09 PM, Matus UHLAR - fantomas wrote:
On 27.01.18 11:16, CP wrote:
I'm trying to eliminate a problem with duplicate emails in alias
expansion
and I have seen that some (local generated and SMTP also) messages
don't have the
Message-ID header . I'm reading in in postconf that there is a
configuration
option always_add_missing_headers that does exactly that. If I
enable this
option do I get in any risk of braking anything in my existing setup ?
The manual refers that " this may break DKIM signatures that cover
non-existent headers"
but I'm not sure if that refers to local generated messages or
everything received my SMTP.
I'm not currently using DKIM in my setup.
If you receive dkim-signed mail without message-id, but the dkim
signature
will claim it contains message-id too (does this happen?), and when
you add
it, the message will not pass the check (including your message-id
changes
the hash).
So far I have only seen messages without the message-id header , is
there some way to
check for what you're describing above in received message headers ?
this should not be a problem if you aren't resending the mail to outside,
and can be avoided by checking the DKIM before message-id is added and
never
later.
Usually I don't resend the message but users might forward the message to
an outside recipient, this is not the case I hope ?
Checking DKIM is done by postfix ? any further info or reading about
this ?
Thanks In advance
