ALL_TRUSTED RULE due to sendmail to Mailscanner relay

[Matt Kettler]

Brett Carruthers wrote:
> Hi,
> 
> I was hoping someone could nudge me in the correct direction.
> 
> My configuration has led me to have all of my mail to be listed as 
> trusted due to sendmail sending the mail to mailscanner. Can I stop this 
> extra header being written into the mail so my spam scores are not being 
> lowered? The ALL_TRUSTED_RULE is giving each message a -1.80 score.
> 
> I use sendmail and Mailscanner with FProt antivirus before mail reaches 
> our mail server Scalix.

If your mailscanner server resolves "mailserv.iii.net.au " as a reserved IP (ie: 
10.* or 192.168.*, 172... etc) then you need to set your trusted_networks manually.

SpamAssassin uses a trust-path guessing algorithm, but that algorithm assumes 
the first public IP is your MX. However, that assumption breaks when your MX is 
NAT mapped.

The fix is to declare trusted_networks manually, to give SA explicit 
instructions about what hosts are trusted. It won't try to auto guess then.

(and no, there's no reliable sure-fire way for SA to figure out what your 
network topology is based on the headers.. it makes its best guess)..

See also:

http://wiki.apache.org/spamassassin/TrustPath