Cisco Cisco Email Security Appliance X1050 Guía Del Usuario
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Cisco IronPort AsyncOS 7.1 for Email Configuration Guide
OL-22158-02
Chapter 8 Anti-Spam
Incoming Relays
The Incoming Relays feature helps your IronPort appliance obtain the IP address
of an external machine that is sending mail to the IronPort appliance via one or
more mail exchange/transfer agents (MX or MTA), filtering servers, etc. at the
edge of the network. In this type of configuration, the IP address of the external
machine is not automatically known by the IronPort appliance. Instead, mail
appears to originate from the local MX/MTA (the incoming relay) rather than
from the external machine. IronPort Anti-Spam and IronPort Intelligent
Multi-Scan depend on accurate IP addresses for external senders so it is vital for
the IronPort appliance to have this information.
of an external machine that is sending mail to the IronPort appliance via one or
more mail exchange/transfer agents (MX or MTA), filtering servers, etc. at the
edge of the network. In this type of configuration, the IP address of the external
machine is not automatically known by the IronPort appliance. Instead, mail
appears to originate from the local MX/MTA (the incoming relay) rather than
from the external machine. IronPort Anti-Spam and IronPort Intelligent
Multi-Scan depend on accurate IP addresses for external senders so it is vital for
the IronPort appliance to have this information.
Note
You should only enable this feature if you have a local MX/MTA relaying mail to
your IronPort appliance.
your IronPort appliance.
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 IronPort appliance.
MX/MTA is relaying mail to the IronPort appliance.