Using DNS blacklists
This feature is not enabled by default. Please follow these instructions to enable it!
The each domain can reject mail if the sending machine's IP address is listed on one of the blacklists compiled by [Spamhaus http://www.spamhaus.org]. These lists contain IP addresses that fulfil various criteria, and it is prudent to check which lists are suitable for your purposes before enabling them. The blacklists available are as follows:
- sbl.spamhaus.org -- the Spamhaus Block List
- xbl.spamhaus.org -- the Exploits Block List
- pbl.spamhaus.org -- the Policy Block List
- sbl-xbl.spamhaus.org -- a combination of the first two lists
- zen.spamhaus.org -- a combination of the first three lists
To enable rejection based on any one of these lists, simply create a file with the same name as the list you'd like to use in a domain's config directory.
NB it is wise to check the listing criteria for each list you intend to use before using it!
For example to enable rejection using the zen.spamhaus.org list for example.com, create the file /srv/example.com/config/zen.spamhaus.org.
Another example: to enable rejection using both the sbl.spamhaus.org and pbl.spamhaus.org lists for example.org, create the files /srv/example.com/config/sbl.spamhaus.org and /srv/example.com/config/pbl.spamhaus.org.
