RBLs
From Mac OS X Server FAQ
What is a Real-time Blackhole List
Real-time Blackhole Lists (RBLs) attempt to track sources of spam via IP addresses. There are two reasons for you to be concerned with RBLs on Mac OS X Server.
- You would like to use software that queries a RBL so you may reject spam before it reaches your users inbox.
- You have been listed on an RBL and, as a result, your mail is being rejected by spam filtering software at sites your users are attempting to mail to.
Using a RBL
If you would like to use an RBL in conjunction with a product like SpamAssassin opinion varies widely on which particular RBL is the best/most accurate. Each list has a certain character and level of aggressiveness which may or may not suit your organization. Among the most widely used are:
http://www.spamhaus.org/<br> http://www.spamcop.net/<br> http://www.mail-abuse.com/<br>
But there are many sources:<br> http://www.email-policy.com/Spam-black-lists.htm
Installing_Virus_and_Spam_protection software on your OS X Server, and including these various lists in your filtering process, will reduce the flow of spam into your user's mailboxes. Finally, there are some cogent arguments against using RBLs at all.
If you have been listed on a RBL
Most often non-marketing institutions are listed on RBLs because they have an open-relay on their system. The Open Relay Database maintains a good FAQ on the subject.
Closing open relays on OS X Server is not difficult. Mail-Abuse.com has hints on fixing your other systems.
To see if you have an open relay you can submit yourself to the testing service at Abuse.net. They offer two testing types, both of which will NOT be reported to a RBL (but they will be logged). This is preferable to the tests provided by organizations like ORDB which, if you fail, will cause you to be listed on their RBL immediately.
There is no one-stop-shopping to be de-listed. Generally, being de-listed requires visiting several sites, each of which should have sent an email to the postmaster account on your server warning you that you had been listed. Most organizations providing RBLs have delisting/testing information as a link from their main page.
