Cisco Cisco Email Security Appliance C170 Guia Do Utilizador

9-100

User Guide for AsyncOS 9.8 for Cisco Email Security Appliances

Chapter 9 Using Message Filters to Enforce Email Policies

Using the CLI to Manage Message Filters

The first prompt determines whether or not a message header’s encoding should be changed to match
that of the message body if the header is changed (via a filter, for example).

The second prompt controls whether or not the appliance should impose the encoding of the message
body on the header if the header is not properly tagged with a character set.

The third prompt is used to configure how disclaimer stamping (and multiple encodings) in the message
body works. Please see “Disclaimer Stamping and Multiple Encodings” in the “Text Resources” chapter
for more information.

Sample Message Filters

In the following example, the

filter

command is used to create three new filters:

•

The first filter is named

big_messages

. It uses the

body-size

rule to drop messages larger than 10

megabytes.

•

The second filter is named

no_mp3s

. It uses the

attachment-filename

rule to drop messages that

contain attachments with the filename extension of

.mp3

•

The third filter is named

mailfrompm

. It uses

mail-from

rule examines all mail from

postmaster@example.com

and blind-carbon copies

administrator@example.com

Using the

filter -> list

subcommand, the filters are listed to confirm that they are active and valid,

and then the first and last filters are switched in position using the

move

subcommand. Finally, the

changes are committed so that the filters take effect.

- SETUP - Configure multi-lingual settings.

mail3.example.com> filters

Choose the operation you want to perform:

- NEW - Create a new filter.

- IMPORT - Import a filter script from a file.

[]> new

Enter filter script. Enter '.' on its own line to end.

big_messages:

if (body-size >= 10M) {

drop();

}