Cisco Cisco Email Security Appliance C680 User Guide

Large corporate data centers can share one IronPort M-Series appliance acting as 
an external IronPort Spam quarantine for one or more IronPort C- or X-Series 
appliances. Further, remote offices can be set up to maintain their own local 
IronPort appliance quarantines for local use (using the local IronPort Spam 
quarantine on C- or X-Series appliances).

 shows a typical network configuration incorporating the IronPort 

M-Series appliance and multiple DMZs. Incoming mail from the Internet is 
received by the IronPort appliances in the outer DMZ. Clean mail is sent along to 
the MTA (groupware) in the inner DMZ and eventually to the end users within the 
corporate network.

Spam and suspected spam (depending on your mail flow policy settings) is sent 
to the IronPort M-Series appliance’s Spam quarantine. End users may then access 
the quarantine and elect to delete spam and release messages they would like to 
have delivered to themselves. Messages remaining in the IronPort Spam 
quarantine are automatically deleted after a configurable amount of time (see the 
“Quarantines” chapter in the Cisco IronPort AsyncOS for Email Daily 
Management Guide).

Mail is sent to the IronPort M-Series appliance from other IronPort (C- and 
X-Series) appliances. An IronPort appliance that is configured to send mail to an 
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 

Internal Users

Outer DMZ

Inner DMZ

C-Series Appliance

Groupware

C-Series Appliance

C-Series Appliance

M-Series Appliance

Corporate 

Network