340
01-28008-0013-20050204
Fortinet Inc.
DNSBL & ORDBL
Spam filter
Figure 179:Adding an IP address
3
Enter the IP address/mask you want to add.
4
If required, select before or after another IP address in the list to place the new IP
address in the correct position.
5
Select the action to take on email from the IP address.
6
Select OK.
DNSBL & ORDBL
Using DNSBLs (DNS-based Blackhole Lists) and ORDBLs (Open Relay Database
Lists) is an effective way to tag or reject spam as it enters your system. These lists act
as domain name servers that match the domain of incoming email to a list of IP
addresses known to send spam or allow spam to pass through. DNSBLs keep track of
reported spam source addresses and ORDBLs keep track of unsecured third party
SMTP servers, known as open relays, which some spammers use to send unsolicited
bulk email.
There are also several free and subscription servers available that provide reliable
access to continually updated DNSBLs and ORDBLs. Check with the service you are
using to confirm the correct domain name for connecting to the server.
The FortiGate unit communicates with DNSBL servers using UDP through port 53.
The FortiGate unit compares the IP address or domain name of the sender to any
database lists you configure. The FortiGate unit checks all the servers in the list
simultaneously. If a match is found, the corresponding protection profile action is
taken. If no match is found, the email is passed on to the next spam filter.
This section describes:
•
DNSBL & ORDBL list
•
DNSBL & ORDBL options
•
Configuring the DNSBL & ORDBL list
Note:
Because the FortiGate unit uses the server domain name to connect to the DNSBL or
ORDBL server, it must be able to look up this name on the DNS server. For information on
configuring DNS, see
“DNS” on page 68
.
Summary of Contents for FortiGate FortiGate-5020
Page 86: ...86 01 28008 0013 20050204 Fortinet Inc Dynamic IP System DHCP ...
Page 118: ...118 01 28008 0013 20050204 Fortinet Inc FortiManager System Config ...
Page 254: ...254 01 28008 0013 20050204 Fortinet Inc CLI configuration User ...
Page 318: ...318 01 28008 0013 20050204 Fortinet Inc CLI configuration Antivirus ...
Page 350: ...350 01 28008 0013 20050204 Fortinet Inc Using Perl regular expressions Spam filter ...
Page 370: ...370 01 28008 0013 20050204 Fortinet Inc CLI configuration Log Report ...
Page 382: ...382 01 28008 0013 20050204 Fortinet Inc Glossary ...
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