At the end of this is actually the default boiler-plate file from the distribution pretty much as is. If you want, you can modify your boiler plate as well as your installed policy-builder.sh script. Who can use us as outbound relay. Who really are our MX clients. You can substitute this knowledge with a fuzzy feeling by using 'acceptifmx -' attribute at the generic boilerplate.
List here domain names.
The policy-builder.sh builds this file from external sources. SMTP clients won't react on that properly, and will just keep repeating the delivery attempts. You can delay the rejections until RCPT addresses are given. 2.1 Immediate rejection by RBL Like mentioned above, this method has a problem with many clients who don't believe that HELO can give 500-series response. Unspecified bits must be 0.