Thinking about DCC

Vernon Schryver
Fri Oct 4 18:15:48 UTC 2013

> From: "Sig Pam" <>

> What happens to maillist subscriptions?
> For example, as an Oracle Professional, me and some thousend more receive an
> alert e-mail on new and critical bugs. To you, this must look like SPAM.
> Does DCC handle this? How? 

Spam is unsolicited bulk mail.
Mailing list messages that are not spam are solicited bulk mail.
DCC detects bulk mail, both solicitied and unsolicited.

DCC is designed to distinguish solicited from unsolicited bulk mail
with per-user and per-organization white lists.  The DCC client
programs, dccm, dccproc, and dccifd, consult /var/dcc/whiteclnt and
/var/dcc/userdirs/local/$USER/whiteclnt files.  Those files should
contain lines for streams of solicited bulk mail.
The DCC source contains proof-of-concept cgi scripts to help
users maintain individual whiteclnt files.
with user name cgi-demo and password cgi-demo

However, most installations add DCC results to SpamAssassin scores.
>From the DCC point of view, SpamAssassin is used as substitute for
bulk mail whitelists.  From the SpamAssassin point of view, DCC is
used to detect bulk mail and "bulk" is a blackmark that is not proof
of spam.

Vernon Schryver

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