Re: [Exim] Rejecting Email with bad sender MX

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Author: Dave C.
Date:  
To: RN.MailLists
CC: exim-users
Subject: Re: [Exim] Rejecting Email with bad sender MX
Added in v 3.161:


                  27. ADDITIONAL GENERIC OPTIONS FOR ROUTERS


The following additional generic options apply to all routers, in
addition to the common generic options for both directors and routers
which are described in chapter 20. Routers are concerned with addresses
whose domains do not match something in "local_domains".

ignore_target_hosts      Type: host list*          Default: unset


Although this option is a host list, it would normally contain IP
address entries rather than names. If any host that is looked up by the
router matches an item in this list, Exim behaves as if the host did
not exist. This option allows you to cope with rogue DNS entries like

some.remote.domain A 127.0.0.1

by setting

ignore_target_hosts = 127.0.0.1

on the relevant router. Attempts to mail to such a domain then receive
the 'unrouteable domain' error, and verifications fail. This option may
also be useful for ignoring link local IPv6 addresses. The string value
of "ignore_target_hosts" is expanded before use as a list, so it is
possible to make it dependent on the domain that is being routed.


On Tue, 6 Feb 2001, Rick Ballard wrote:

> Lately I have been seeing spam with such DNS oddities as
> MX=127.0.0.1 or MX=192.168.1.1. This is obviously purposely
> misconfigured.
>
> How can I just kill this junk on sight ? I want
> to fail incoming mail based on the sender's MX
> record.
>
> --------------- Example 1
>
> MX points to 192.168.1.1
>
> 2001-02-06 08:48:30 14Q6e2-00002E-00
> misdirected.buydomains.com [192.168.1.1]: No
> route to host
>
> mail1:~$ nslookup
> > set type=mx
> > accessmaster.com
> accessmaster.com        preference = 0, mail
>     exchanger = misdirected.buydomains.com
> accessmaster.com        nameserver =
>     ns.buydomains.com
> misdirected.buydomains.com      internet address
>     = 192.168.1.1
> ns.buydomains.com       internet address =
>     207.32.91.110

>
> --------------- Example 2
>
> MX points to 127.0.0.1
>
> 2001-02-03 20:24:51 lowest numbered MX record
> points to local host: giveaway.com (while
> verifying <justforyou@???> from host
> (anydomain.com) [154.5.39.84])
>
> mail1:~$ nslookup
> > set type=mx
> > giveaway.com
> giveaway.com    preference = 20, mail exchanger
> = mail.giveaway.com
> giveaway.com    nameserver =
> dns.fastdnsservers.com
> giveaway.com    nameserver =
> dns2.fastdnsservers.com
> mail.giveaway.com       internet address =
> 127.0.0.1

>
>
>
> --
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
> Rick Ballard            Rick.Ballard@???
> Halifax, Nova Scotia, Canada    http://www3.ns.sympatico.ca/Rick.Ballard

>
> --
> ## List details at http://www.exim.org/mailman/listinfo/exim-users Exim details at http://www.exim.org/ ##
>


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