Cisco Cisco Email Security Appliance C170 Guia Do Utilizador

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 of the Cisco IronPort AsyncOS 
for Email Advanced Configuration Guide. This allows the Cisco IronPort 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 in the Cisco IronPort AsyncOS for Email 
Advanced Configuration Guide.

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 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 of the Cisco IronPort AsyncOS for Email 
Advanced Configuration Guide.

For more information about masquerading via an LDAP query, see the “LDAP Queries” chapter in the 
Cisco IronPort AsyncOS for Email Advanced Configuration Guide. 

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

For more information, see “LDAP Queries” in the Cisco IronPort AsyncOS for Email Advanced 
Configuration Guide.