Two opposing DCC outputs

Vernon Schryver vjs@rhyolite.com
Fri Oct 17 04:46:42 UTC 2014


> From: Chris <cpollock@embarqmail.com>
> To: dcc@rhyolite.com

> Spamassassin 3.4.0, DCC 1.3.155, I had a couple of posts come in to my
> spam folder today from Time Warner Cable. They both had the below
> markups which confuses me since one says they're listed in DCC and the
> other says DCC check is negative or am I misinterpreting this?
>
> 2.2 DCC_CHECK              listed in DCC
> (http://rhyolite.com/anti-spam/dcc/)
> -0.0 DCC_CHECK_NEGATIVE     Not listed in DCC

Without knowing a lot more about your SpamAssassin installation and
the rest of what SpamAssasin said, and probably not even then,
I can't say anything about what that SpamAssassin text means.

If then that SpamAssassin text means that the message was checked
in DCC more than once, there are some things to be said.
Asking DCC about a single messages more than once is easy, undesirable,
and sometimes unaviodable.  When that does happen, DCC results can
change.  One possibility is that text is added to the message between
the first and last DCC check, making the message appear to be two
different messages to DCC.

Another possibility comes from the fact that the consensus DCC database
is dynamic.  If reports about the message arrive DCC clients between
the first and last DCC check, then the last results can differ.  This
is releated to the main reason why repeated DCC checks on a single
message are undesirable.  Unless the later checks are "queries" instead
of "reports", they will increase the number of copies of the message
seen by DCC, and so potentially make a message appear "bulkier."

A /var/dcc/whiteclnt "MX" or "MXDCC" line can often prevent that
message copy count inflation as described in the main DCC man page
on your system or at
http:/www.dcc-servers.net/dcc/dcc.html#White-and-Blacklists


Vernon Schryver    vjs@rhyolite.com



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