User Guide

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AsyncOS 9.1.2 for Cisco Email Security Appliances User Guide
Chapter 24 Configuring Routing and Delivery Features
Configuring Mail Gateways for all Hosted Domains Using Virtual Gateway™ Technology
To specify which IP interface or interface group the system will deliver email from, you create mapping
keys that pair either the sender’s IP address or the Envelope Sender address to an IP interface or interface
group (specified by interface name or group name).
AsyncOS will compare both the IP address and Envelope Sender address to the mapping keys. If either
the IP address or Envelope Sender address matches one of the keys, the corresponding IP interface is
used for the outbound delivery. If there is no match, the default outbound interface will be used.
The system can match any of the following keys and take preference in the following order:
Note A listener checks the information in the altsrchost table and directs the email to a particular interface
after checking the masquerading information and before message filters are checked.
Use these subcommands within the
altsrchost command to create mappings in the Virtual Gateways
via the CLI:
Importing an altsrchost File
Like the HAT, the RAT, smtproutes, and masquerading and alias tables, you can modify altsrchost
entries by exporting and importing a file.
Procedure
Step 1 Use the export subcommand of the altsrchost command to export the existing entries to a file (whose
name you specify).
Step 2 Outside of the CLI, get the file. (See Appendix A, “FTP, SSH, and SCP Access” for more information.)
Step 3 With a text editor, create new entries in the file. The order that rules appear in the altsrchost table is
important.
Step 4 Save the file and place it in the “altsrchost” directory for the interface so that it can be imported. (See
Appendix A, “FTP, SSH, and SCP Access” for more information.)
Sender’s IP address
The IP address of the sender must match exactly.
Example:
192.168.1.5
Fully-formed Envelope
Sender
The Envelope Sender must match the entire address exactly.
Example:
[e-mail]
Username
The system will match username syntax against the Envelope Sender address
up to the
@ sign. The @ sign must be included. Example: username@
Domain
The system will match domain name syntax against the Envelope Sender
address starting with the
@ sign. The @ sign must be included. Example:
@example.com
Syntax Description
new
Create a new mapping manually.
print
Display the current list of mappings.
delete
Remove one of the mappings from the table.