What are the BASIC pre-configured rules?

The BASIC pre-configured rules are preset rules that mostly occur before Praetor's Bayesian statistical filtering.  These are performed first in order to eliminate the statistical possibility that:

• undesirable messages (e.g. suspicious attachments) may be deemed as good, and

• desirable messages may be detected to have spam characteristics.

The following are the pre-filter rules performed by Praetor, and indicated by log entries that start with "SYS_" in the rule name reflecting its system-internal nature, e.g. "SYS_DNS Blacklisted message".

1. Reject messages from sources listed on the DNSBL server(s)

2. Reject messages that contain any attachment found on the banned attachment list

3. Quarantine messages that contain any attachment found on the suspicious attachment list

4. Accept messages from senders on the approved address list

5. Accept messages from senders in any approved domain list

6. Accept messages from senders on the approved listserver address list

7. Bayesian filter tests for spam and non-spam based upon the cut-off values for bad and good mail

8. Quarantine messages containing invisible HTML ink, where the color of the text is so close to the background that the text is not readable

9. Quarantine messages containing tiny HTML text

10. Quarantine messages containing obfuscated URLs, or links containing IP addresses instead of domain names or port numbers

11. Accept messages with computed spamicity in the unsure range, between the two cut-off values.

As these rules are pre-configured, their order cannot be changed.  If you want to deviate from this order you will need to select the ADVANCED message level filtering on the configure spam filter screen shown below.

Choosing ADVANCED will allow you to configure the rules in your chosen order which also include the three enabled rules involving Bayesian spamicity tests seen below.  

  Note:

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