Cisco Cisco Email Security Appliance C190 Guía Del Usuario
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Cisco AsyncOS 8.5.5 for Email Security User Guide
Chapter 13 Anti-Spam
Determining Sender IP Address In Deployments with Incoming Relays
What To Do Next
Consider doing the following:
•
Add the relaying machine to a sender group with a mail flow policy that has unlimited messages for
DHAP. For an explanation, see
DHAP. For an explanation, see
•
To facilitate tracking and troubleshooting, configure the appliance logs to show which header is
used. See
used. See
Related Topics
•
Message Headers for Relayed Messages
You will configure your appliance to use one of the following types of header to identify the original
sender of a relayed message:
sender of a relayed message:
•
•
Custom Header
Using custom headers is the recommended method of identifying original senders. The machine
connecting to the original sender needs to add this custom header. The value of the header is expected
to be the IP address of the external sending machine. For example:
connecting to the original sender needs to add this custom header. The value of the header is expected
to be the IP address of the external sending machine. For example:
SenderIP: 7.8.9.1
X-CustomHeader: 7.8.9.1
If your local MX/MTA can receive mail from a variable number of hops, inserting a custom header is
the only way to enable the Incoming Relays feature. For example, in
the only way to enable the Incoming Relays feature. For example, in
to IP address 10.2.3.5; however, path C has two hops and path D has one. Because the number of hops
can vary in this situation, you must use a custom header in order to have Incoming Relays configured
correctly.
can vary in this situation, you must use a custom header in order to have Incoming Relays configured
correctly.