ZyXEL Communications 3.1 User Manual

Chapter 24 Anti-Spam

ZyWALL (ZLD) CLI Reference Guide

This example shows how to configure and enable a white list entries for e-mails with “testwhite” in 
the subject, e-mails from whitelist@ourcompany.com, e-mails with the Date header set to 2007, 
and e-mails from (or forwarded by) IP address 192.168.1.0 with subnet 255.255.255.0.   

The following applies for a black or white list entry based on an e-mail subject, e-mail address, or 
e-mail header value.

• Use a question mark (?) to let a single character vary. For example, use “a?c” (without the 

quotation marks) to specify abc, acc and so on. 

• You can also use a wildcard (*). For example, if you configure *def.com, any e-mail address that 

ends in def.com matches. So “mail.def.com” matches.

• The wildcard can be anywhere in the text string and you can use more than one wildcard. You 

cannot use two wildcards side by side, there must be other characters between them. 

• The ZyWALL checks the first header with the name you specified in the entry. So if the e-mail has 

more than one “Received” header, the ZyWALL checks the first one.

This section describes the commands for checking the sender and relay IP addresses in e-mail 
headers against DNS (Domain Name Service)-based spam Black Lists (DNSBLs). You must use the 

configure terminal

 command to enter the configuration mode before you can use these 

commands.

The following table identifies the values required for many of these commands. Other input values 
are discussed with the corresponding commands.

Router(config)# anti-spam white-list subject testwhite activate

Router(config)# anti-spam white-list e-mail whitelist@ourcompany.com activate

Router(config)# anti-spam white-list mail-header Date 2007 activate

Router(config)# anti-spam white-list ip-address 192.168.1.0 255.255.255.0 activate

Router(config)# show anti-spam white-list

No.   Type        Status

Content

==========================================================================

1     subject     yes

testwhite

2     e-mail      yes

whitelist@ourcompany.com

3     mail-header yes

Date : 2007

4     ip-address  yes

192.168.1.0 / 255.255.255.0

Input Values for DNSBL Commands

A domain that is maintaining a DNSBL. You may use 0-254 alphanumeric characters, or 
dashes (-).