Hi.
btw: Thanks for your efforts in answering my questions, and sorry for
posting to -devel before (did not notice in the beginning, that this
is not meant for bug/feature reports).
Quoting Wietse Venema <wie...@porcupine.org>:
clients (depending on local_header_rewrite_clients) and for remote
clients only if remote_header_rewrite_domain is not empty.
This only trips up people who can't read what the text says, and
instead read what they want to read.
Well,... I just got confused as I saw the envelope addresses to be
rewritten in my logs,.. sorry.
- Envelope sender and recipient addresses are ALWAYS (regardless of
Indeed. Does the documentation ever claim otherwise?
No not really.
http://www.postfix.org/ADDRESS_REWRITING_README.html#standard ,
http://www.postfix.org/postconf.5.html#append_dot_mydomain ,
http://www.postfix.org/postconf.5.html#append_at_myorigin and
say addresses which refers as I know understand to both (envelope and
header). But they're also refer to the remote_header_rewrite_domain and
local_header_rewrite_clients and the later rewrite chapters directly
named envelope and header addresses...
So again,.. this confused me probably a little bit. My fault, sorry!
In case you wonder why bare name is handled as n...@$myorigin,
this is because doing otherwise would open a giant hole in the
Postfix defenses (people would have to specify more access rules).
Not sure if understand what you mean.
Anyway,.. it seems that it's possible for a remote client to send mail
that looks as if it would come from the host postfix is running on,
right?!
Either as just "root" or "r...@host" (without the domain) if
append_dot_mydomain = no and remote_header_rewrite_domain is empty.
But even if not empty a remote client could still simply use
r...@host.domain.tld as sender.
Of course I understand that mail does not guarantee sender
authenticity but this is still a security problem, isn't it?
I mean it's easily possible to reject reject_non_fqdn_sender and I
think even envelope sender addresses that match any of the canonical
domains,.. but this doesn't help with the headers.
Is there an easy way for this problem? Or do I misunderstand something.
Cheers,
Chris.
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