ZyXEL Communications USG-300 - V2.20 ED 2, Руководство пользователя

Страница: 703 / 1149

Chapter 38 Anti-Spam
ZyWALL USG 300 User’s Guide
703
The following table describes the labels in this screen.
Table 187 Configuration > Anti-X > Anti-Spam > DNSBL
LABEL DESCRIPTION
Show Advance
Settings / Hide
Advance Settings Click this button to display a greater or lesser number of configuration
fields.
Enable DNS Black
List (DNSBL)
Checking 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.
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
Checking Per Mail Set the maximum number of sender and relay server IP addresses in
the mail header to check against the DNSBL domain servers.
IP Selection Per
Mail 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.
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.