Spam thru secondary MX

[Matt Kettler]

<x-flowed>
At 05:24 AM 8/30/2004, Peter Kruit wrote:
>I've been running MailScanner/SpamAssassin and RBL checks in sendmail for 6
>months now and the amount of spam has gone down quiet a bit. Recently I've
>noticed that spam is being delivered thru my secondary MX. I don't have
>access to the secondary MX because it's offsite and owned by another
>company. They do not filter for spam. Can I somehow configure MailScanner
>or SpamAssassin to check for example the first (or all) IP in the message
>header against the RBLs I use?

SpamAssassin checks all IP's in all Received: headers against RBL's by
default. No settings required.

One exception to this is dialup RBLs, which in 2.6x are only checked
against hosts dropping mail off to a machine listed in trusted_networks.

You can manually set your trusted networks, and in it include the secondary
MX, your primary MX, and any other mailservers that insert Received:
headers that are a part of your network which should not get mail directly
from dialups.


However don't make the common mistake of assuming "trusted" means
"whitelisted".

         Trusted in 2.6x means "mailserver in my home network, trusted to
not forge Received: headers, and should never receive mail directly from
dialup".

         3.0 behaves differently with separate settings for "trusted to not
forge" and "part of local network", and adds a new one for "whitelisted
from RBL checks".

  See man Mail::SpamAssassin::Conf for details on configuring this setting.

------------------------ MailScanner list ------------------------
To unsubscribe, email jiscmail at jiscmail.ac.uk with the words:
'leave mailscanner' in the body of the email.
Before posting, read the MAQ (http://www.mailscanner.biz/maq/) and
the archives (http://www.jiscmail.ac.uk/lists/mailscanner.html).
</x-flowed>