The Dnsbl Screen - ZyXEL Communications ZyWALL USG 300 User Manual

Chapter 35 Anti-Spam

35.6 The DNSBL Screen

Click Anti-X > Anti-Spam > DNSBL to display the anti-spam DNSBL screen.
Use this screen to configure the ZyWALL to check the sender and relay IP
addresses in e-mail headers against DNS (Domain Name Service)-based spam
Black Lists (DNSBLs).
Figure 420 Anti-X > Anti-Spam > DNSBL
The following table describes the labels in this screen.
Table 180 Anti-X > Anti-Spam > DNSBL
LABEL
Enable DNS Black
List (DNSBL)
Checking
DNSBL Spam Tag
Max. IPs
Checking Per Mail
IP Selection Per
Mail
610
DESCRIPTION
Select this to have the ZyWALL check the sender and relay IP
addresses in e-mail headers against the DNSBL servers maintained
by the DNSBL domains listed in the ZyWALL.
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.
Set up to how many sender and relay server IP addresses in the mail
header to check against the DNSBL.
Select first N IPs to have the ZyWALL start checking from the first IP
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.
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