SpamCensor changes for upgrade to MailMarshal Exchange 5.2

This article applies to:

• MailMarshal Exchange 5.2
• SpamCensor functionality

Question:

• What are the recommended SpamCensor rules for MailMarshal Exchange 5.2?
• Upgrading to MailMarshal Exchange version 5.2 removes the SpamCensor external command
• Need new SpamCensor rules for MailMarshal Exchange 5.2

Information:

MailMarshal Exchange 5.2 provides an integrated SpamCensor facility similar to the SpamCensor in MailMarshal SMTP.

This facility includes automated updating, and a new rule condition "where message is categorized as."

When you upgrade to MailMarshal Exchange 5.2 from version 5.1, the upgrade process removes the SpamCensor external command, and disables any rules that use it.

To configure SpamCensor with MailMarshal Exchange 5.2, follow the steps in this article.

Procedure:

1. If necessary, configure proxy settings for automatic updates. See the Internet Access tab of Server Properties.
2. Enable automatic updates. See the Spam Updates tab of Server Properties.
3. Create new rules to implement SpamCensor. See the listing below.

Recommended SpamCensor rules:

Trustwave recommends the following minimum set of rules to implement SpamCensor and other filtering that is automatically updated through the SpamCensor update.

• For more information about creating rulesets and rules, see the User Guide and Help.
• In addition to the rules, you may need to create classifications and folders. You can create the classifications and folders while you are creating the rules.

1. Create the rules in an inbound ruleset. This should be in your first inbound policy ruleset. An example of a ruleset is shown below:



2. Create rules as follows. Note that the "where addressed to" and "except where addressed to" information is automatically populated from the ruleset.

Standard Rule: Block Known Threats
This rule invokes an XML Category script to search inbound messages for patterns associated with known worms and viruses. This rule is automatically updated by Marshal to maintain effectiveness. In addition, you can add to the Known Threats User script when nasty new threats appear. If the rule detects patterns associated with known threats it will quarantine the message and notify the local recipient(s).
When a message arrives
Where addressed to '[ExampleDomain] Domain Users'
    Except where addressed from '[ExampleDomain] Domain Users'
Where message is categorized as 'Known Threats'
Send a 'Worm In' notification message
    And write log message(s) with 'Virus Suspected'
    And move the message to 'Virus Suspected'

Standard Rule: Block Virus - Zero Day Protection Framework
This rule invokes the ZeroDay Threats category script. The script is updated automatically, with new ZeroDay updates published intermittently in response to specific threat outbreaks. It is intended to be a short-term measure to protect you until the "Known Threats" script is updated to deal with the outbreak.
When a message arrives
Where addressed to '[ExampleDomain] Domain Users'
    Except where addressed from '[ExampleDomain] Domain Users'
Where message is categorized as 'Zero Day Threats'
Send a 'Worm In' notification message
    And write log message(s) with 'Virus Suspected'
    And move the message to 'Virus Suspected'

Standard Rule: Block Spam - SpamCensor
This rule uses the MailMarshal SpamCensor filter to identify spam messages based on a scoring system. Messages that exceed 60 points are quarantined to the 'Spam' folder. The SpamCensor filter is a special type of Category Script that is automatically updated by Marshal.
When a message arrives
Where addressed to '[ExampleDomain] Domain Users'
    Except where addressed from '[ExampleDomain] Domain Users'
Where message attachment size is less than '200 KB'
    And where message is categorized as 'Spam'
Write log message(s) with 'Contains Spam'
    And move the message to 'Spam'

Standard Rule: Block Spam - Zero Day Protection Framework
This rule uses the ZeroDay spam filter to identify new spam outbreaks which may be missed by the standard SpamCensor. The filter is updated automatically, with new ZeroDay updates published intermittently in response to specific outbreaks. It is intended to be a short-term measure to protect you until the SpamCensor is updated to deal with the outbreak.
When a message arrives
Where addressed to '[ExampleDomain] Domain Users'
    Except where addressed from '[ExampleDomain] Domain Users'
Where message is categorized as 'ZeroDay Spam'
Write log message(s) with 'Contains Spam'
    And move the message to 'Spam'