The "lack", as it were, is in your thinking through the problem.
There is no way, short of sender authentication, to tell whether an
incoming message which has a sender address in your domain is
legitimate or forged. Consider the case of a mailing list hosted at
another site (the qmail list), as an example. Would you like to
start rejecting incoming mail from the qmail list if the sender was
yourself?
-- Jeff Hayward
On Tue, 27 Apr 1999 [EMAIL PROTECTED] wrote:
I have found a lack in qmail's configuration options
that I don't know how to solve.
I want to use qmail as smtp gateway. I have
configured qmail to relay mail selectively from our
mail servers. It seems to me little elegant to
manage this away qmail's control files but it really
works. Maybe I could apply Rask Ingemann
Lambertsen's patch (to add control/relayclients and
control/relaydomains files) but I don't know if it's
recommended.
However I don't know how to manage forged senders
with our own domain when it's received from
Internet. If I include our domain in
control/badmailfrom file, valid mail from our mail
servers also is rejected. Otherwhise our users could
receive mail that seems internal. DNS checking
doesn't help because our domain is valid.
I know that Internet Mail isn't authenticaded at
all, withouth using digital signatures (PGP,
S/MIME), but I think that accepting notorious forged
mail is an error and even more if could be passed
off as internal message.
Thanks in advance for your help,
David Jorrin.
====
David Jorrin <[EMAIL PROTECTED]>
"This chapter is about Laziness, Impatience
and Hubris because this chapter is about
good software design"
Larry Wall, Tom Christiansen &
Randal L. Schwartz [Programming Perl]
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