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60 Barracuda Spam Firewall Administrator’s Guide

The following table describes each of the blacklist settings on the Block/Accept > External Blacklist

page.

Blacklist Services Descriptions

The following table describes each blacklist service available.

Table 5.1:

Blacklist Setting Description

Barracuda Blacklist Whether the blacklist maintained by Barracuda Networks is enabled.

The Barracuda blacklist contains servers that are manually verified for

sending large amounts of spam.

Common External Blacklists Activate or deactivate blacklist services that are built into the Barracuda

Spam Firewall by changing the selected action for the given blacklist(s)

and clicking the Save Changes button.

Custom External Blacklists Free or subscription blacklists that you want to use. After entering the

external blacklist, specify the action you want performed. Click Add and

then Save Changes when finished.

You can locate blacklists on the Internet by searching for DNSBL or

RBL. However, be cautious and use only trusted blacklists.

Blacklist Options Delay RBL Check—Determines whether RBL checks are performed

after the RCPT TO is given.

Setting this option to Yes causes RBL checks to run after the RCPT TO

is given in the SMTP transaction. This allows the sender/recipient

information to appear in the message log.

Setting this option to No results in only the IP being available in the

message log entry.

Blacklist Using Full Header Scan—Set to Yes to let the Barracuda

Spam Firewall scan e-mail headers for blacklisted IP addresses.

Scanning headers can impact system performance because the

Barracuda Spam Firewall needs to do a DNS lookup for each header.

For this reason, you should only enable this feature if mail from the

Internet is not delivered directly to the Barracuda Spam Firewall.

Table 5.2:

Blacklist Service Description

sbl.spamhaus.org Spamhaus tracks the Internet's Spammers, Spam Gangs and Spam

Services, provides dependable realtime anti-spam protection for

Internet networks, and works with law enforcement to identify and

pursue spammers worldwide

xbl.spamhaus.org To help stop the increase of spam from illegal exploits, Spamhaus

released the Exploits Block List (XBL). This list is a realtime DNS-

based database of IP addresses of illegal third-party exploits, including

open proxies, worms/viruses with built-in spam engines, and other

types of trojan-horse exploits used by spammers.

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