Cisco Cisco Email Security Appliance C160 Mode D'Emploi

Note, as a general rule, changes to security services (anti-spam scanning, anti-virus scanning, and 
Outbreak Filters) do not affect messages already in the work queue. As an example:

If a message bypasses anti-virus scanning when it first enters the pipeline because of any of these 
reasons:

anti-virus scanning was not enabled globally for the appliance, or

the HAT policy was to skip anti-virus scanning, or

there was a message filter that caused the message to bypass anti-virus scanning,

then the message will not be anti-virus scanned upon release from the quarantine, regardless of whether 
anti-virus scanning has been re-enabled. However, messages that bypass anti-virus scanning due to mail 
policies may be anti-virus scanned upon release from a quarantine, as the mail policy's settings may have 
changed while the message was in the quarantine. For example, if a message bypasses anti-virus 
scanning due to a mail policy and is quarantined, then, prior to release from the quarantine, the mail 
policy is updated to include anti-virus scanning, the message will be anti-virus scanned upon release 
from the quarantine.

Similarly, suppose you had inadvertently disabled anti-spam scanning globally (or within the HAT), and 
you notice this after mail is in the work queue. Enabling anti-spam at that point will not cause the 
messages in the work queue to be anti-spam scanned.

You can use your existing LDAP infrastructure to define how the recipient email address of incoming 
messages (on a public listener) should be handled during the SMTP conversation or within the 
workqueue. See “Accept Queries” in the “Customizing Listeners” chapter. This allows the appliance to 
combat directory harvest attacks (DHAP) in a unique way: the system accepts the message and performs 
the LDAP acceptance validation within the SMTP conversation or the work queue. If the recipient is not 
found in the LDAP directory, you can configure the system to perform a delayed bounce or drop the 
message entirely.

For more information, see the “LDAP Queries” chapter.

Masquerading is a feature that rewrites the envelope sender (also known as the sender, or 

MAIL FROM

) 

and the To:, From:, and/or CC: headers on email processed by a private or public listener according to a 
table you construct. You can specify different masquerading parameters for each listener you create in 
one of two ways: via a static mapping table, or via an LDAP query.

For more information about masquerading via a static mapping table, see “Configuring Masquerading” 
in the “Configuring Routing and Delivery Features” chapter.

For more information about masquerading via an LDAP query, see the “LDAP Queries” chapter. 

You can configure your appliance to route messages to the appropriate address and/or mail host based 
upon the information available in LDAP directories on your network.