On Tue, 15 Aug 2006, Guy Waugh wrote:
|# Theo Van Dinter wrote:
|# > On Tue, Aug 15, 2006 at 08:41:27AM +1000, Guy Waugh wrote:
|# >
|# > > Aug 15 05:01:35 mailserver sendmail[13287]: k7EJ1YE7013287: SYSERR(root):
|# > > localhost.fabulous.com. config error: mail loops back to me (MX problem?)
|# > >
|# The above stuff appears in my logs when, for example, our MX receives
|# spam for an unknown local user and tries to bounce the mail back to the
|# sender. The sender domain's MX resolves to 127.0.0.1 (or similar), and
|# the above occurs. I was thinking of a test whereby something on my MTA
|# looks up the MX of every sender domain of every email, and if it
|# resolves to localhost, the email is rejected (discarded/whatever) at
|# that point.
|#
In Postfix one can do this simply with the following.....
# grep 127 mx-ns_cidr_access (file containing CIDR blocks)
127.0.0.0/8 REJECT Loopback Address 127.0.0.0/8
in main.cf (whatever restriction class you choose)...
check_sender_mx_access cidr:mx-ns_cidr_access
--
Tim Rosmus <[EMAIL PROTECTED]>
Postmaster / USENET / DNS
Northwest Nexus Inc. / NetOS Inc.
