Cisco Cisco Email Security Appliance C160 Mode D'Emploi

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 listener according to a table that you construct. A typical example 
implementation of this feature is “Virtual Domains,” which allows you to host 
multiple domains from a single site. Another typical implementation is “hiding” 
your network infrastructure by “stripping” the subdomains from strings in email 
headers. The Masquerading feature is available for both private and public 
listeners. 

The Masquerading feature is configured on a per-listener basis, as opposed to the 
Alias Tables functionality, which is configured for the entire system. 

A listener checks the masquerading table for matches and modifies the recipients 
while the message is in the work queue, immediately after LDAP recipient 
acceptance queries and before LDAP routing queries. Refer to “Understanding the 
Email Pipeline” in the Cisco IronPort AsyncOS for Email Configuration Guide.

The Masquerading feature actually rewrites addresses for the Envelope Sender 
and the To:, From:, and CC: fields of the email that has been received. You can 
specify different masquerading parameters for each listener you create in one of 
two ways:

via a static table of mappings you create, or 

via an LDAP query.

 

This section discusses the static table method. The table format is 
forward-compatible with the 

/etc/mail/genericstable

 feature of a sendmail 

configuration on some Unix systems. See 

 for more 

information on LDAP masquerading queries.