Cisco Cisco Email Security Appliance C170 Betriebsanweisung
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User Guide for AsyncOS 10.0 for Cisco Email Security Appliances
Chapter 13 Anti-Spam
Determining Sender IP Address In Deployments with Incoming Relays
For more information, see
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Determining Sender IP Address In Deployments with Incoming
Relays
Relays
If one or more mail exchange/transfer agents (MX or MTA), filtering servers, etc. stand at the edge of
your network, between your Cisco appliance and the external machines that are sending incoming mail,
then your appliance cannot determine the IP addresses of the sending machines. Instead, mail appears to
originate from the local MX/MTA. However, IronPort Anti-Spam and Cisco Intelligent Multi-Scan
(using the SenderBase Reputation Service) depend on accurate IP addresses for external senders.
your network, between your Cisco appliance and the external machines that are sending incoming mail,
then your appliance cannot determine the IP addresses of the sending machines. Instead, mail appears to
originate from the local MX/MTA. However, IronPort Anti-Spam and Cisco Intelligent Multi-Scan
(using the SenderBase Reputation Service) depend on accurate IP addresses for external senders.
The solution is to configure your appliance to work with incoming relays. You specify the names and IP
addresses of all of the internal MX/MTAs connecting to the Cisco appliance, as well as the header used
to store the originating IP address.
addresses of all of the internal MX/MTAs connecting to the Cisco appliance, as well as the header used
to store the originating IP address.
Related Topics
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Example Environments with Incoming Relays
shows a very basic example of an incoming relay. Mail from IP address 7.8.9.1 appears to
come from IP address 10.2.3.4 because the local MX/MTA is relaying mail to the Cisco appliance.