Cisco Cisco Email Security Appliance C160 Mode D'Emploi
7-4
User Guide for AsyncOS 9.7 for Cisco Email Security Appliances
Chapter 7 Defining Which Hosts Are Allowed to Connect Using the Host Access Table (HAT)
Defining Remote Hosts into Sender Groups
Sender Group Syntax
Sender Groups Defined by Network Owners, Domains, and IP Addresses
Since the SMTP protocol has no built-in method for authenticating senders of email, senders of
unsolicited bulk email have been successful at employing a number of tactics for hiding their identity.
Examples include spoofing the Envelope Sender address on a message, using a forged HELO address,
unsolicited bulk email have been successful at employing a number of tactics for hiding their identity.
Examples include spoofing the Envelope Sender address on a message, using a forged HELO address,
Table 7-1
Defining Remote Hosts in the HAT: Sender Group Syntax
Syntax
Meaning
n:n:n:n:n:n:n:n
IPv6 address; does not need to include leading zeroes.
n:n:n:n:n:n:n:n-
n:n:n:n:n:n:n:n
n:n:n-n:n:n:n:n:n
Range of IPv6 addresses; does not need to include leading zeroes.
n.n.n.n
Full (complete) IPv4 Address
n.n.n.
n.n.n
n.n.
n.n
n.
n
Partial IPv4 address
n.n.n.n-n
n.n.n-n.
n.n.n-n
n.n-n.
n.n-n
n-n.
n-n
Range of IPv4 addresses
yourhost.example.com
A fully-qualified domain name
.partialhost
Everything within the partialhost domain
n/c
n.n/c
n.n.n/c
n.n.n.n/c
IPv4 CIDR address block
n:n:n:n:n:n:n:n/c
IPv6 CIDR address block; does not need to include leading zeroes
SBRS[n:n]
SBRS[none]
SenderBase Reputation Score. For more information, see
SBO:n
SenderBase Network Owner Identification Number. For more
information, see
information, see
dnslist[dnsserver.domain]
DNS List query. For more information, see
.
ALL
Special keyword that matches ALL addresses. This applies only to
the ALL sender group, and is always included (but not listed).
the ALL sender group, and is always included (but not listed).