Cisco Cisco Email Security Appliance C160 Mode D'Emploi
2-8
Cisco IronPort AsyncOS 7.6 for Email Advanced Configuration Guide
OL-25137-01
Chapter 2 Configuring Routing and Delivery Features
provides an overview of the various features used for rewriting sender and recipient email
addresses.
Creating Alias Tables
Alias tables provide a mechanism to redirect messages to one or more recipients. You can construct a
mapping table of aliases to usernames and other aliases in a similar fashion to the
mapping table of aliases to usernames and other aliases in a similar fashion to the
/etc/mail/aliases
feature of a sendmail configuration on some Unix systems.
When the Envelope Recipient (also known as the Envelope To, or
RCPT TO
) of an email accepted by a
listener matches an alias as defined in an alias table, the Envelope Recipient address of the email will be
rewritten.
rewritten.
Note
A listener checks the alias table and modifies the recipients after checking the RAT and before message
filters. Refer to “Understanding the Email Pipeline” in the Cisco IronPort AsyncOS for Email
Configuration Guide.
filters. Refer to “Understanding the Email Pipeline” in the Cisco IronPort AsyncOS for Email
Configuration Guide.
Note
The Alias Table functionality actually rewrites the Envelope Recipient of the email. This is different than
the
the
smtproutes
command (see
), which does not rewrite the
Envelope Recipient of the email, but instead simply reroutes the email to specified domains.
Configuring an Alias Table from the Command Line
Alias tables are defined in sections as follows: each section is headed by a domain context, which is a
list of domains that the section is relevant to, followed by a list of maps.
list of domains that the section is relevant to, followed by a list of maps.
A domain context is a list of one or more domains or partial domains, separated by commas and enclosed
in square brackets ('
in square brackets ('
[
' and '
]
'). A domain is a string containing letters, digits hyphens, and periods as
defined in RFC 1035, section 2.3.1., “Preferred name syntax.” A partial domain, such as
.example.com
is a domain that begins with a period. All domains that end with a substring matching the partial domain
Table 2-1
Methods for Rewriting Addresses
Original Address
Change to
Feature
Works on
*@anydomain
user@domain
Alias Tables (see
•
Envelope Recipients only
•
Applied globally
•
Maps aliases to email
addresses or other aliases
addresses or other aliases
*@olddomain
*@newdomain
Domain Mapping (see
)
•
Envelope Recipients only
•
Applied per listener
*@olddomain
*@newdomain
Masquerading (see
)
•
Envelope Sender and the
To:, From:, and/or CC:
headers
To:, From:, and/or CC:
headers
•
Applied per listener