On 2/21/2013 2:51 PM, Jeff Mincy wrote:
From: "Kevin A. McGrail" <kmcgr...@pccc.com>
Date: Thu, 21 Feb 2013 11:07:20 -0500
On 2/21/2013 10:36 AM, Matus UHLAR - fantomas wrote:
> And how is this ISP's issue related to RFCs? The RFC does not mention
> word
> "trusted"
A fair point that I didn't explain clearly enough.
The RFCs cover received headers for SMTP and RFCs strive to be black and
white. Discussing things as gray area is an argument that Bill Clinton
was famous for but doesn't really hold a place in discussing technology
covered by
Which RFC talks about Received headers having rDNS or what information
is supposed to be in the received header?
Off-hand, I don't know that any specific RFC spells out that exact
requirement.
For SMTP, it's http://tools.ietf.org/html/rfc5321#section-3.7.2 along
with some others that add requirements for the received header (1651, I
think adds ESMTP requirements).
Overall, though Received is considered debug/trace information and
pre-existing headers shouldn't be modified when received.
But I do believe it's generally accepted that one of the primary
original uses for rDNS was for received headers in SMTP. I don't think
anything requires it. Someone on this list will know for sure.
The point of SA's trusted configuration is that you "trust" the
headers. In this case, he's saying he doesn't trust the headers because
they are omitting important information but that they aren't lying, just
lying by ommissions. To me, this says "I can't trust those headers"
and you need to pull back your trust circle which in this case will ruin
much of the rules SA uses for pathway analysis (RBLs, rDNS, etc.)
Fixing those headers outside SA or fixing the ISP creating those headers
are the real solutions.
There is of course a third option for me - I could turn off the spam
filtering on Rcn email. Most of the spam is blocked by Rcn, there's
almost no point in trying to filter what little spam is left.
Agreed. It's unusual these days to have to improve on the upstream
provider much more than the junk filters built into MUAs like
Thunderbird and Outlook.
regards,
KAM
