IronPort - Configuration Guide - AsyncOS 7.6.1

Chapter 1 Getting Started with the Cisco IronPort Email Security Appliance
Mail Flow and the Cisco IronPort M-Series Appliance
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If you include an M-Series appliance in your configuration, mail is sent to the Cisco IronPort M-Series
appliance from other Cisco IronPort (C- and X-Series) appliances. A Cisco IronPort appliance that is
configured to send mail to a Cisco IronPort M-Series appliance will automatically expect to receive mail
released from the M-Series appliance and will not re-process those messages when they are received
back — messages will bypass the HAT and other policy or scanning settings and be delivered. For this
to work, the IP address of the Cisco IronPort M-Series appliance must not change. If the IP address of
the Cisco IronPort M-Series appliance changes, the receiving C- or X-Series appliance will process the
message as it would any other incoming message. Always use the same IP address for receiving and
delivery on the Cisco IronPort M-Series appliance.
The Cisco IronPort M-Series appliance accepts mail for quarantining from the IP addresses specified in
the Cisco IronPort Spam Quarantine settings. To configure the local quarantine on the Cisco IronPort
M-Series appliance see the Cisco IronPort AsyncOS for Security Management User Guide . Note that the
local quarantine on the Cisco IronPort M-Series appliance is referred to as an external quarantine by the
other Cisco IronPort appliances sending mail to it.
Mail released by the Cisco IronPort M-Series appliance is delivered to the primary and secondary hosts
(Cisco IronPort appliance or other groupware host) as defined in the Spam Quarantine Settings (see the
Cisco IronPort AsyncOS for Security Management User Guide ). Therefore, regardless of the number of
Cisco IronPort appliances delivering mail to the Cisco IronPort M-Series appliance, all released mail,
notifications, and alerts are sent to a single host (groupware or Cisco IronPort appliance). Take care to
not overburden the primary host for delivery from the Cisco IronPort M-Series appliance.
Cisco IronPort AsyncOS 7.6 for Email Configuration Guide
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