dccm and dccd (greylist) - Another newbie-

Vernon Schryver vjs@calcite.rhyolite.com
Sat Jan 14 15:24:50 UTC 2006


> From: Dean Maluski <dmaluski@n1ety.com>
> Reply-To: dmaluski@n1ety.com


> Finally about a week ago I came across a document in MailScannerf wiki
> that I felt would guide me through getting DCC up and running properly.

> http://wiki.mailscanner.info/doku.php?id=documentation:anti_spam:spamassassin:plugins:dcc:dccm_instead&s=Spamassassin
> I setup DCC following this document.

Why not let sendmail+dccm reject spam?  Why complicate it by involving
SpamAssassin?  I guess that Mailscanner recipe is intended to use the
greylisting of sendmail+dccm but rejecting bulk mail only if SpamAssassin
finds some bad signs and without going to the trouble of maintaining a
local whitelist.

As I've said many times, I think is wrong.  The right way to use the
DCC has nothing to do with SpamAssassin.  Assuming you are using sendmail,
it consists of:

  - installing dccm as described in the INSTALL.txt or .html file

  - letting sendmail+dccm reject unsolicited bulk email
      To do that, sent DCCM_REJECT_AT in /var/dcc/dcc_conf to what
      you consider "bulk".  Common choices range from 5 to 500, with
      small values appropriate for small sites

   - using site-local as well as per-user logs and whitelists to
      identify solicited bulk email.
      To do that, follow comments in /var/dcc/dcc_conf about setting
      DCCM_LOG_AT= your notion of bulk, leaving DCCM_REJECT_AT blank,
      and monitoring bulk mail in /var/dcc/log.  Each time you see
      solicited bulk mail, whitelist the sender.
      That can be done by pointing-and-clicking if you set up the
      CGI scripts as described in /var/dcc/cgi-bin/README.



> 2.17	DCC_CHECK_HDR	Use of 'dccm' header to mimic DCC_CHECK

I cannot find the string "mimi" anywhere in Mail-SpamAssassin-3.1.0
Are you sure you are using Mail-SpamAssassin-3.1.0?


> Also in my dcc subdirectory there is no dcc_db except when I created a
> file of such name thinking that perhaps if it's found it will start to
> build.

Since you are not running a local DCC server but instead using the
public DCC servers, why do you want a dcc_db file?

> Also the timestamp on grey_db and grey_db.hash never change and their
> byte size remain the same.

The support for mmap() in Linux is the weakest among contemporary
UNIX-like operating.  That the mtime of a mapped file doesn't eventually
change after it is modified is the least of the mmap() bugs in at least
some versions of Linux.  However, why do you care?  What problem is
this causing?

>                            It seems they get rebuilt within about a half
> hour after I rename them.

Why are you renaming them?


Vernon Schryver    vjs@rhyolite.com



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