Cisco Cisco Email Security Appliance C170 사용자 가이드
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Cisco IronPort AsyncOS 7.1 for Email Configuration Guide
OL-22158-02
Chapter 7 Reputation Filtering
identity of senders. The SenderBase Reputation Service is similar to a credit
reporting service for email; it provides data that enterprises can use to
differentiate legitimate senders from spam sources. Integrated directly into the
IronPort appliance GUI, the SenderBase Reputation Service provides objective
data that allows you to identify reliably and block IP addresses originating
unsolicited commercial email (UCE) or to verify the authenticity of legitimate
incoming email from business partners, customers, or any other important source.
The SenderBase Reputation Service is unique in that it provides a global view of
email message volume and organizes the data in a way that makes it easy to
identify and group related sources of email.
reporting service for email; it provides data that enterprises can use to
differentiate legitimate senders from spam sources. Integrated directly into the
IronPort appliance GUI, the SenderBase Reputation Service provides objective
data that allows you to identify reliably and block IP addresses originating
unsolicited commercial email (UCE) or to verify the authenticity of legitimate
incoming email from business partners, customers, or any other important source.
The SenderBase Reputation Service is unique in that it provides a global view of
email message volume and organizes the data in a way that makes it easy to
identify and group related sources of email.
Note
If your IronPort appliance is set to receive mail from a local MX/MTA, you must
identify upstream hosts that may mask the sender's IP address. See
identify upstream hosts that may mask the sender's IP address. See
for more information.
Several key elements of the SenderBase Reputation Service are that it is:
•
Non-spoofable
The email sender’s reputation is based on the IP addresses of the email sender.
Because SMTP is a two-way conversation over TCP/IP, it is nearly impossible to
“spoof” an IP address — the IP address presented must actually be controlled by
the server sending the message.
Because SMTP is a two-way conversation over TCP/IP, it is nearly impossible to
“spoof” an IP address — the IP address presented must actually be controlled by
the server sending the message.
•
Comprehensive
The SenderBase Reputation Service uses global data from the SenderBase
Affiliate network such as complaint rates and message volume statistics as well
as data from carefully selected public blacklists and open proxy lists to determine
the probability that a message from a given source is spam.
Affiliate network such as complaint rates and message volume statistics as well
as data from carefully selected public blacklists and open proxy lists to determine
the probability that a message from a given source is spam.
•
Configurable
Unlike other “identity-based” anti-spam techniques like blacklists or whitelists
that return a simple yes/no decision, the SenderBase Reputation Service returns a
graduated response based on the probability that a message from that source is
spam. This allows you to set your own threshold for where you choose to block
spam and automatically assign senders to different groups based on their
SenderBase Reputation Score.
that return a simple yes/no decision, the SenderBase Reputation Service returns a
graduated response based on the probability that a message from that source is
spam. This allows you to set your own threshold for where you choose to block
spam and automatically assign senders to different groups based on their
SenderBase Reputation Score.