On 1/5/2012 12:46 AM, Eric Lemings wrote: > The RBL sites come from various Postfix tutorials on the web, many of which > are getting woefully dated. Thanks for the updates.
First, please use the generic term "dnsbl" instead of "RBL". RBL is a copyrighted/trademarked term specific to MAPS Corporation. Regarding the various Postfix tutorials scattered all over the web, yes, many are very outdated. I wouldn't necessarily trust the dnsbls listed in them if the article is more than a few years old as dnsbls tend to come and go. Often when they die they end up listing "the world" which may cause your MTA to reject all mail. Typing spam source IP addresses into this: http://www.mxtoolbox.com/blacklists.aspx will show if the IP is listed by any of 100 or so active dnsbls. You can then research those that seem to "catch your spam" regularly, and add them to your config, if you like their listings and management policies. Most listed are free of charge, some require a subscription. As a general rule, you should kill spam by any and all other means within Postfix _before_ querying a remote dnsbl. The reasons are two fold: 1. MTA latency is lower, overall performance higher 2. dnsbl operator network overhead is lower -- Stan
