Chapter 34 Anti-Spam

The following table describes the labels in this screen.

Table 169 Configuration > Anti-X > Anti-Spam > DNSBL

LABEL

DESCRIPTION

Show Advance

Click this button to display a greater or lesser number of configuration

Settings / Hide

fields.

Advance Settings

 

 

 

Enable DNS Black

Select this to have the ZyWALL check the sender and relay IP

List (DNSBL)

addresses in e-mail headers against the DNSBL servers maintained by

Checking

the DNSBL domains listed in the ZyWALL.

 

 

DNSBL Spam Tag

Enter a message or label (up to 15 ASCII characters) to add to the

 

beginning of the mail subject of e-mails that have a sender or relay IP

 

address in the header that matches a black list maintained by one of

 

the DNSBL domains listed in the ZyWALL.

 

This tag is only added if the anti-spam policy is configured to forward

 

spam mail with a spam tag.

 

 

Max. IPs

Set the maximum number of sender and relay server IP addresses in

Checking Per Mail

the mail header to check against the DNSBL domain servers.

 

 

IP Selection Per

Select first N IPs to have the ZyWALL start checking from the first IP

Mail

address in the mail header. This is the IP of the sender or the first

 

server that forwarded the mail.

 

Select last N IPs to have the ZyWALL start checking from the last IP

 

address in the mail header. This is the IP of the last server that

 

forwarded the mail.

 

 

Query Timeout

 

Setting

 

 

 

SMTP

Select how the ZyWALL is to handle SMTP mail (mail going to an e-

 

mail server) if the queries to the DNSBL domains time out.

 

Select drop to discard SMTP mail.

 

Select forward to allow SMTP mail to go through.

 

Select forward with tag to add a DNSBL timeout tag to the mail

 

subject of an SMTP mail and send it.

 

 

POP3

Select how the ZyWALL is to handle POP3 mail (mail coming to an e-

 

mail client) if the queries to the DNSBL domains time out.

 

Select forward to allow POP3 mail to go through.

 

Select forward with tag to add a DNSBL timeout tag to the mail

 

subject of an POP3 mail and send it.

 

 

Timeout Value

Set how long the ZyWALL waits for a reply from the DNSBL domains

 

listed below. If there is no reply before this time period expires, the

 

ZyWALL takes the action defined in the relevant Actions when

 

Query Timeout field.

 

 

Timeout Tag

Enter a message or label (up to 15 ASCII characters) to add to the

 

mail subject of e-mails that the ZyWALL forwards if queries to the

 

DNSBL domains time out.

 

 

DNSBL Domain

 

List

 

 

 

Add

Click this to create a new entry.

 

 

 

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ZyWALL USG 50 User’s Guide