-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1
On Tue, Oct 24, 2006 at 10:22:26PM -0400, 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?
Thanks
jerry
dnl # dnl # dnsbl - DNS based Blackhole List/Black List/Rejection list dnl # See http://www.sendmail.org/m4/features.html#dnsbl dnl # FEATURE(`dnsbl', `bl.spamcop.net', `"Spam blocked see: http://spamcop.net/bl.shtml?%22$&%7Bclient_addr%7D%27)dnl FEATURE(`dnsbl', `relays.ordb.org', `"Spam blocked see: http://ordb.org/lookup/?host=%22$&%7Bclient_addr%7D%27)dnl FEATURE(`dnsbl', `cbl.abuseat.org', `"Spam blocked see: http://cbl.abuseat.org/lookup.cgi?ip=%22$&%7Bclient_addr%7D%27)dnl FEATURE(`dnsbl', `sbl.spamhaus.org', `"Spam blocked see: http://spamhaus.org/query/bl?ip=%22$&%7Bclient_addr%7D%27)dnl FEATURE(`dnsbl', `list.dsbl.org', `"Spam blocked see: http://dsbl.org/listing?%22$&%7Bclient_addr%7D%27)dnl dnl #
There have been a lot of replies (some very good) on this subject already, but I feel I have to drop my 2 cents on this subject, since spam control is a good part of what I do.
It is fairly trivial to get to a point where you have a spam control system with 75% efficiency (with 1% to 2% false positives). Just implementing RBLs, greylisting and spamassassin will do that. SPF might also help a bit here.
Wish a bit more work, you can get to 85% efficiency, keeping the same level of false positives (rate limiting and various access control rules).
After that point, it starts to get ugly. We currently manage to have 96% efficiency (false positives around 0.001%), and thats a daily battle. Spam traps and new rules almost every day (5 days a week, at least).
For those interested, these are the RBLs I use: sbl-xbl.spamhaus.org relays.ordb.org dnsbl.njabl.org
Dropped spamcop some months ago.
[]s
- -- Rodrigo Barbosa "Quid quid Latine dictum sit, altum viditur" "Be excellent to each other ..." - Bill & Ted (Wyld Stallyns)