Symantec Mail Security, Руководство администратора

Страница: 98 / 258

98 Configuring email filtering
Managing Email Firewall policies
How Symantec Mail Security for SMTP identifies senders and
connections
The following sections provide details about the Allowed Senders Lists and
Blocked Senders Lists.
Supported Methods for Identifying Senders
You can use the following methods to identify senders for your Allowed Senders
Lists and Blocked Senders Lists.
■
Domain-based: specify sender addresses or domain names
Symantec Mail Security for SMTP checks the following characteristics of
incoming mail against those in your lists:
■
MAIL FROM: address in the SMTP envelope. Specify a pattern that
matches the value for localpart@domain in the address. You can use
the * or ? wildcards in the pattern to match any portion of the address.
■
From:
address in the message headers. Specify a pattern that matches
the value for localpart@domain in the
From:
header. You can use
wildcards in the pattern to match any portion of this value.
If you choose to identify messages by address or domain name, see Table 4-
12 for examples.
An individual is sending
unwanted mail to people in
your organization. Add the specific email address to the
domain-based Blocked Senders List. Joe.unwanted*@getmail.com
Numerous people from a
specific range of IP addresses
are sending unsolicited mail to
people in your organization. After analyzing the received headers to
determine the sender's network and IP
address, add the IP address and net mask to
the IP-based Blocked Senders List. 218.187.0.0/255.255.0.0
Table 4-11 Use cases for lists of allowed and blocked senders (Continued)
Problem Solution Pattern example
Table 4-12 Matches for email addresses or domain names
Example Sample matches
example.com chang@example.com, marta@example.com,
foo@bar.example.com
malcolm@example.net malcolm@example.net
sara*@example.org sara@example.org, sarahjane@example.org
jo??@example.corg john@example.org, josh@example.org