Marvin Modules: Whitelist & Blacklist

Whitelist
The whitelist is the first anti-spam configurable process that e-mail passes through. Using the web interface, you can configure patterns to match IP addresses, domain names, senders, subjects, and even the message body itself. Whitelist rules are processed in order and if there is a match, the message is immediately delivered. If a message doesn't pass any whitelist rules, it can still be delivered since it passes on to the next process.

The most obvious use of the whitelist is to ensure that messages from certain senders always get through. Another way to use it is for mailing lists. Many mailing lists put a common pattern in the subject line, so you can be sure that you receive all messages sent to the list. Yet another possibility is to look for a keyword in the subject line to use as a password. You can give this password out to people to make sure you get mail from them.

The whitelist process comes first so you can guarantee delivery for specific messages, even if the message would normally be failed by another process. Messages that pass a whitelist rule do not go through any of the other programs. They are immediately delivered.

Blacklist
The next process is the blacklist. A blacklist is the opposite of a whitelist. You define patterns to match IP addresses, domain names, sender, subject, or the message body. If a message matches any blacklist rules, it is automatically failed. It does not pass go, and it does not collect $200.

Blacklists aren't extremely useful for stopping spam, since spammers use techniques like serialized subjects and random e-mail addresses, which are designed to get around blacklists. The blacklist feature is included to give users the ability to block mail from a particular sender or a message that contains keywords that are offensive or otherwise inappropriate.

The interface for the whitelist and blacklist are identical. The only difference is how each one works.

Here is what the interface looks like:

IP: Specify an IP address to accept or deny.
Domain: Accept or deny all mail from a particular domain.
From: Accept or deny all mail from a particular e-mail address.
Subject: Specify words and characters in the subject to be accepted/ denied.
Body: Specify text found in the body of the message to be accepted/denied.