Table of Contents

DNSBL (DNS Block List)

Information

Using Spamhaus and Sorbes.

Configuration based on my linux dnsbl configuration

Procedure

  1. Add the following to your /usr/src/etc/sendmail/custom.mc file:
    --- shalom.mc.1.00.0.0  Mon Sep  3 14:45:38 2007
    +++ shalom.mc.1.01.0.0  Mon Sep  3 16:39:45 2007
    @@ -44,7 +44,7 @@
     #
     
     divert(0)
    -VERSIONID(`$FreeBSD: src/etc/sendmail/shalom.mc,v 1.00.0.0 2007/09/02 23:54:00 john Exp $')
    +VERSIONID(`$FreeBSD: src/etc/sendmail/shalom.mc,v 1.01.0.0 2007/09/03 16:33:00 john Exp $')
     OSTYPE(freebsd6)
     DOMAIN(generic)
     
    @@ -67,6 +67,16 @@
     dnl For that, visit
     dnl http://directory.google.com/Top/Computers/Internet/Abuse/Spam/Blacklists/
     
    +dnl# Spamhaus filtering configuration
    +FEATURE(`enhdnsbl',`sbl-xbl.spamhaus.org',`"554 Rejected " $&{client_addr} " found in sbl-xbl.spamhaus.org.  If you think this is an error email root@thoughtbit.com from a different email server."')dnl
    +
    +dnl# Sorbs filtering configuration
    +FEATURE(`dnsbl',`dnsbl.sorbs.net',`"554 Rejected " $&{client_addr} " found in dnsbl.sorbs.net.  If you think this is an error email root@thoughtbit.com from a different email server."')dnl
    +
    +dnl# Allowlist
    +FEATURE(`access_db')dnl
    +FEATURE(`delay_checks',`friend')dnl
    +
     dnl Uncomment to activate Realtime Blackhole List
     dnl information available at http://www.mail-abuse.com/
     dnl NOTE: This is a subscription service as of July 31, 2001
    @@ -88,7 +98,7 @@
     
     define(`confBIND_OPTS', `WorkAroundBrokenAAAA')
     define(`confNO_RCPT_ACTION', `add-to-undisclosed')
    -define(`confPRIVACY_FLAGS', `authwarnings,noexpn,novrfy')
    +define(`confPRIVACY_FLAGS', `authwarnings,noexpn,novrfy,restrictqrun,goaway')
     
     dnl# Also accept mail for localhost.localdomain:
     dnl LOCAL_DOMAIN(`localhost.localdomain')dnl
  2. Rebuild your /usr/src/etc/sendmail/custom.cf file:
    # cd /usr/src/sendmail
    # rm custom.cf
    # m4 -D_CF_DIR_=/usr/src/etc/sendmail/../../contrib/sendmail/cf/   /usr/src/etc/sendmail/../../contrib/sendmail/cf/m4/cf.m4 shalom.mc > shalom.cf
  3. Install your new custom.cf file to /etc/mail/sendmail.cf