Config Spamfilter Rbl; Using Perl Regular Expressions; Regular Expression Vs. Wildcard Match Pattern - Fortinet Fortigate-5000 series Administration Manual

Antispam

config spamfilter rbl

Using Perl regular expressions

Regular expression vs. wildcard match pattern

FortiGate Version 3.0 MR4 Administration Guide
01-30004-0203-20070102
Use the MIME headers list to mark email from certain bulk mail programs or with
certain types of content that are common in spam messages. Mark the email as
spam or clear for each header configured.
Use this command to configure email filtering using DNS-based Blackhole List
(DNSBL), also called Realtime Blackhole List (RBL), and Open Relay Database
List (ORDBL) servers. DNSBL and ORDBL filtering is enabled within each
protection profile.
The FortiGate unit compares the IP address or domain name of the sender to any
database lists configured, in sequence. If a match is found, the corresponding
action is taken. If no match is found, the email is passed on to the next spam filter.
Some spammers use unsecured third party SMTP servers to send unsolicited
bulk email. Using DNSBLs and ORDBLs is an effective way to tag or reject spam
as it enters the network. 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.
There are several free and subscription servers available that provide reliable
access to continually updated DNSBLs and ORDBLs. Please check with the
service being used to confirm the correct domain name for connecting to the
server.
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 "Network Options" on page
Email address list, MIME headers list, and banned word list entries can include
wildcards or Perl regular expressions.
See http://perldoc.perl.org/perlretut.html
regular expressions.
A wildcard character is a special character that represents one or more other
characters. The most commonly used wildcard characters are the asterisk (*),
which typically represents zero or more characters in a string of characters, and
the question mark (?), which typically represents any one character.
In Perl regular expressions, the '.' character refers to any single character. It is
similar to the '?' character in wildcard match pattern. As a result:
• fortinet.com not only matches fortinet.com but also fortinetacom, fortinetbcom,
fortinetccom, and so on.
To match a special character such as '.' and '*' use the escape character '\'. For
example:
• To match fortinet.com, the regular expression should be: fortinet\.com
In Perl regular expressions, '*' means match 0 or more times of the character
before it, not 0 or more times of any character. For example:
Using Perl regular expressions
88.
for detailed information about using Perl
393