User Guide

24-8
AsyncOS 9.1.2 for Cisco Email Security Appliances User Guide
Chapter 24 Configuring Routing and Delivery Features
Creating Alias Tables
A domain context is a list of one or more domains or partial domains, separated by commas and enclosed
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
are considered a match. For example, the domain context
.example.com would match
mars.example.com and venus.example.com. Below the domain context is a list of maps, which are
aliases followed by a list of recipients. A map is constructed as follows:
An alias in the left-hand side can contain the following formats:
You can enter multiple aliases, separated by commas on a single left-hand side line.
Each recipient in the right-hand side can be a full
user@domain email address, or another alias.
An alias file can contain “global” aliases (aliases that are applied globally instead of to a specific
domain) with no implied domain, domain contexts within which aliases have one or more implied
domains, or both.
“Chains” (or recursive entries) of aliases may be created, but they must end in a full email address.
A special destination of
/dev/null is supported to drop the message in order to be compatible with
context of a sendmail configuration. If a message is mapped to
/dev/null via an alias table, the dropped counter is increased. (See the “Managing and Monitoring via
the CLI” chapter.) The recipient is accepted but not enqueued.
Related Topics
• Example Alias Table, page 24-9
• Example aliasconfig Command, page 24-11
Exporting and Importing an Alias Table
To import an alias table, first see Appendix A, “FTP, SSH, and SCP Access” to ensure that you can
access the appliance.
Use the
export subcommand of the aliasconfig command to save any existing alias table. A file (whose
name you specify) will be written to the
/configuration directory for the listener. You can modify this
file outside of the CLI and then re-import it. (If you have malformed entries in the file, errors are printed
when you try to import the file.)
Place the alias table file in the
/configuration directory, and then use the import subcommand of the
aliasconfig command to upload the file.
Comment out lines in the table using a number symbol (#) at the beginning of each line.
Table 24-2 Alias Table Syntax
Left-hand Side (LHS) Separator Right-hand Side (RHS)
a list of one or more aliases to match the colon character
(“
:”)
a list of one or more recipient
addresses or aliases
username
Specifies an alias to match. There must be a preceding “domains” attribute
specified in the table. The lack of this parameter will produce an error.
user@domain
Specifies an exact email address to match on.