Cisco Cisco Email Security Appliance C160 User Guide

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Chapter 1      Getting Started with the Cisco IronPort Email Security Appliance
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Cisco IronPort AsyncOS 7.5 for Email Configuration Guide
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On-box Quarantine areas to hold messages that violate email policies. 
Quarantines seamlessly interact with the Outbreak Filters feature. 
On-box message tracking. AsyncOS for Email includes an on-box message 
tracking feature that makes it easy to find the status of messages that the 
Email Security appliance processes.
Mail Flow Monitoring of all inbound and outbound email that provides 
complete visibility into all email traffic for your enterprise. 
Access control for inbound senders, based upon the sender’s IP address, IP 
address range, or domain. 
Extensive message filtering technology allows you to enforce corporate 
policy and act on specific messages as they enter or leave your corporate 
infrastructure. Filter rules identify messages based on message or attachment 
content, information about the network, message envelope, message headers, 
or message body. Filter actions allow messages to be dropped, bounced, 
archived, blind carbon copied, or altered, or to generate notifications.
Message encryption via secure SMTP over Transport Layer Security 
ensures messages travelling between your corporate infrastructure and other 
trusted hosts are encrypted. 
Virtual Gateway™ technology allows the Cisco IronPort appliance to 
function as several email gateways within a single server, which allows you 
to partition email from different sources or campaigns to be sent over separate 
IP addresses. This ensures that deliverability issues affecting one IP address 
do not impact others.
AsyncOS for Email is a proprietary operating system that has been highly 
optimized for the task of Internet messaging. AsyncOS is a “hardened” operating 
system: all unnecessary services have been removed, which increases security and 
optimizes system performance. Cisco IronPort stackless threading technology 
eliminates allocation of a dedicated memory stack to each task, which increases 
concurrency and stability of the MTA. The custom I/O-driven scheduler is 
optimized for massively concurrent I/O events required by the email gateway 
versus the preemptive time slicing of the CPU in traditional operating systems. 
AsyncFS, the file system underlying AsyncOS, is optimized for millions of small 
files and ensures data recoverability in the case of system failure.
 AsyncOS for email supports RFC 2821-compliant Simple Mail Transfer Protocol 
(SMTP) to accept and deliver messages. The Cisco IronPort appliance is designed 
to be easy to configure and manage. Most reporting, monitoring, and 
configuration commands are available through both the web-based GUI via HTTP