Sendmail and Realtime Blackhole lists
I’ve just updated my sendmail.mc with some RBL’s checks (dnsrbl feature) which is working out quite well. By using Sendmail with dnsrbl checks instead of a anti-spam program such as Mailscanner which also uses the same RBL mechanism you take the advantage of Sendmail dropping the connection before receiving the email. In this case you are not only reducing the amount of spam, but also the system resources and bandwidth.
Hopefully we’ll notice a slight drop in the spam stats I am collecting recently.
If this sounds interesting to you, have a look at the cf/cf/knecht.mc file which comes with your distribution for more information.
Currently I am using the following dnsrbl checks:
FEATURE(`dnsbl‘, `dnsbl.sorbs.net’, `"550 Mail from " $`‘&{client_addr} " refused - see http://www.dnsbl.sorbs.net/"’)
FEATURE(`dnsbl‘, `sbl-xbl.spamhaus.org’, `"550 Mail from " $`‘&{client_addr} " refused - see http://www.spamhaus.org/sbl/"’)
FEATURE(`dnsbl‘, `bl.spamcop.net’, `"450 Mail from " $`‘&{client_addr} " refused - see http://spamcop.net/bl.shtml"’)
FEATURE(`dnsbl‘, `dnsbl.njabl.org’, `"550 Mail from " $`‘&{client_addr} " rejected - see http://njabl.org/"’)
FEATURE(`dnsbl‘, `sbl-xbl.spamhaus.org’, `"550 Mail from " $`‘&{client_addr} " refused - see http://www.spamhaus.org/sbl/"’)
FEATURE(`dnsbl‘, `bl.spamcop.net’, `"450 Mail from " $`‘&{client_addr} " refused - see http://spamcop.net/bl.shtml"’)
FEATURE(`dnsbl‘, `dnsbl.njabl.org’, `"550 Mail from " $`‘&{client_addr} " rejected - see http://njabl.org/"’)
I have big black hole too when I bend over.
maar wel gers, hoor blacklisting. Gebruikt ik hier ook, als eerste verdedigingslinie.
Gebeurdt er hier nog wat?
En is het verbeterd?
En of het verbeterd is! Als je de spam statistieken bekijkt (zie spam stats page) zie je vanaf 9 januari een flinke daling van zeker 60 procent in het aantal spam berichten die het spamassassin filter nog halen.