On Tue, 24 Oct 2006, Jerry Geis wrote:
> Gents,
>
> I have added the following to /etc/mail/sendmail.mc and rebuilt it
> trying to control spam. I still get about 25 spam messages a day. Is
> there something else that can help control spam?
CentOS provides spamassassin 3.0.6, but I've installed spamassassin
3.1.7 and spamass-milter from rpmforge. Running your spam scanner as a
milter allows you to reject egregious during the SMTP transaction.
I haven't done as much tuning as I'd like, but my current setup
includes
INPUT_MAIL_FILTER(
`clamav-milter',
`S=local:/var/clamav/clmilter.sock, F=T, T=S:3m;R:3m')
INPUT_MAIL_FILTER(
`spamassassin',
`S=unix:/var/run/spamass.sock, F=, T=C:15m;S4m;R:4m;E:10m')
define(
`confMILTER_MACROS_CONNECT',
`b, j, _, {daemon_name}, {if_name}, {if_addr}')
FEATURE(`dnsbl', `sbl-xbl.spamhaus.org',
`"554 Mail rejected - http://www.spamhaus.org/query/bl?ip="$&{client_addr}')
The percentage of messages rejected during SMTP transactions breaks
down (for me) like this:
74% == spamhaus
21% == spamassassin
2% == unresolvable sender domain
<1% == clamav
There's a range of spam (scores 5.0 - 10.0) that's accepted for
delivery but marked as spam; people can procmail those as they see
fit.
I think the spamhaus numbers get inflated because the sending servers
are typically bots that are set to try delivery several times before
giving up.
--
Paul Heinlein <> heinlein at madboa.com <> www.madboa.com