Giving spammers a hard time: Conclusion

Summing up:

• High precision

• Good effect, minimal load

• Blacklisting is never better than poorest data source used

  We ended up using Bob Beck's traplist (greytrapping generated) at http://www.openbsd.org/spamd/traplist.gz - as far as we know no false positives

• Prime example: Steve Williams' October 20th, 2006 message to the OpenBSD-misc mailing list - got rid of more than 95% of spam using spamd in pure greylisting mode