Could it be verified that the corpora being submitted for the weekly Network Mass-Checks are coming from systems with correctly configured trusted_networks and internal_networks? It's important for some of the rules, and verifying it works seems inconvenient enough that it might have been skipped, and I could see mail server setups changing over time making old values invalid.
Verification that it's working isn't very straightforward, as far as I can tell. You can add to your configuration: add_header all RelaysUntrusted _RELAYSUNTRUSTED_ And then make sure that in the resulting X-Spam-RelaysUntrusted headers the first IP listed *is* the sending IP, and not an internal relay or proxy or something. For example: X-Spam-RelaysUntrusted: [ ip=74.125.82.173 rdns=mail-wy0-f173.google.com helo=mail-wy0-f173.google.com by=panic.chaosreigns.com ident= envfrom= intl=0 id= auth= msa=0 ] Received: from mail-wy0-f173.google.com (mail-wy0-f173.google.com [74.125.82.173]) by panic.chaosreigns.com (Postfix) with ESMTP for <dar...@chaosreigns.com>; Sun, 17 Oct 2010 16:47:52 -0400 (EDT) The IP 74.125.82.173 from the X-Spam-RelaysUntrusted header matches the Received header from the last untrusted relay. -- "Let's just say that if complete and utter chaos was lightning, then he'd be the sort to stand on a hilltop in a thunderstorm wearing wet copper armour and shouting 'All gods are bastards'." - The Color of Magic http://www.ChaosReigns.com