> In general, can people provide me with some statistics > from their own servers showing just how good the phrase > and statistical filtering are compared to RBLs?
Hi Andrew, This is a little bit of work, but fortunately I've made such a research yesterday. I'm talking here about Spam-filtering with declude junkmail. The RBL-test are listed on http://www.declude.com/junkmail/support/ip4r.htm You can see a number followed by the name of the RBL-test. The number indicates the positive test results in the timerange (15 hours) I've made the research. 429 NOMOREFUNN Looks good, but checking manualy the log-files I've counted over 65% of FP's Bad test! 302 EASYNET-DNSBL Haven't found any FP in the logs. But from 50 messages failing this test 47 has failed also at least 3 other ip4r-tests. (MonkeyforProxies, SpamCop, OSProxy, OSSoft, SBL, DSBL...) 186 DSBL 141 SPAMCOP 124 MONKEYPROXIES 113 SBL 112 OSPROXY 94 OSSOFT 87 OSSRC The same thing for all this tests. Looks like a combination of all this tests (where each one has as weight of 25% of the hold value) is a very solid indicator for spam. Remains the ip4r-test from place 10 to 20: I've noted that specialy the BHOLE-tests catch spam messages that are not covered by the other ip4r-tests. I haven't found any FP vote from a BHOLE test, but on our server we have practicaly no traffic from this countries. So I'm not sure how good the BHOLE-tests are working. 47 BHOLE-CHINA 47 BHOLE-CN-KR 41 VOX 30 OSRELAY 26 OSDIPS 25 INTERSIL 24 BHOLE-KOREA 20 BHOLE-BRAZIL 17 NJABL 16 ORDB 11 OSDUL Up to here the results for RBL. Now I've analyzed the results in the same timerange for SpamChk (a free Addon for Declude Junkmail, specialized on content based spam detection) SpamChk has given 2120 votes. 940 of them has had a positive result. The other 1180 votes was negative, indicating legit content. If SpamChk can find some reliable indicator for a legit message it will give also a negative weight as result. SpamChk makes around 25 content based tests, and returns his opinion about the message content back to the declude weighting system. >From the 1180 messages with a negative spamchk-vote: * 472 has also failed declude's NOLEGITCONTENT test. * only 5 has failed any of the above ip4r-tests, except for NOMOREFUNN Markus To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
