spamassassin-users October 2010 archive
Main Archive Page > Month Archives  > spamassassin-users archives
spamassassin-users: Re: Whitelist questions

Re: Whitelist questions

From: Karsten Bräckelmann <guenther_at_nospam>
Date: Tue Oct 05 2010 - 15:30:06 GMT
To: users@spamassassin.apache.org

On Tue, 2010-10-05 at 10:40 -0400, Alex wrote:
> I have an email that I'm trying to whitelist using whitelist_from_rcvd
> and it's not working as I expect. I've created an entry:
>
> whitelist_from_rcvd user@lanyon.com savvis.net
>
> Here is the corresponding received header:
>
> X-Envelope-From: <user@lanyon.com>
> Received: from S253906HZ1EW06.usstls6-hosting.savvis.net (unknown
> [209.16.192.170])
>
> Is it because there is no reverse DNS entry?

As the documentation [1] clearly states, the second value (a) is a
string matched against the relay's rDNS in the Received headers, and
(b) it is your MX's responsibility to perform the rDNS lookup and add it
to the header.

The latter is key, because despite "no reverse DNS entry" being
ambiguous, there actually is an rDNS entry for the IP. In DNS, it's
merely missing from the Received header.

  $ host 209.16.192.170
  170.192.16.209.in-addr.arpa domain name pointer Lanyon.com.

So, fix your MX. :) With an rDNS entry in the header, you will need to
adjust your whitelist setting to use the actual rDNS, rather than the
savvis.net HELO mystery.

[1] http://spamassassin.apache.org/full/3.2.x/doc/Mail_SpamAssassin_Conf.html#whitelist_and_blacklist_options

-- char *t="\10pse\0r\0dtu\0.@ghno\x4e\xc8\x79\xf4\xab\x51\x8a\x10\xf4\xf4\xc4"; main(){ char h,m=h=*t++,*x=t+2*h,c,i,l=*x,s=0; for (i=0;i<l;i++){ i%8? c<<=1: (c=*++x); c&128 && (s+=h); if (!(h>>=1)||!t[s+h]){ putchar(t[s]);h=m;s=0; }}}