Cisco Cisco Email Security Appliance C190 Guía Del Usuario
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AsyncOS 9.1.2 for Cisco Email Security Appliances User Guide
Chapter 7 Defining Which Hosts Are Allowed to Connect Using the Host Access Table (HAT)
Handling Messages from a Group of Senders in the Same Manner
Max. Recipients per Time
Interval
Interval
The maximum number of recipients during a specified time period that
this listener will receive from a unique envelope sender, based on the
mail-from address. The number of recipients is tracked globally. Each
listener tracks its own rate limiting threshold; however, because all
listeners validate against a single counter, it is more likely that the rate
limit will be exceeded if messages from the same mail-from address are
received by multiple listeners.
this listener will receive from a unique envelope sender, based on the
mail-from address. The number of recipients is tracked globally. Each
listener tracks its own rate limiting threshold; however, because all
listeners validate against a single counter, it is more likely that the rate
limit will be exceeded if messages from the same mail-from address are
received by multiple listeners.
Select whether to use the default maximum recipients, accept unlimited
recipients, or specify another maximum number of recipients.
recipients, or specify another maximum number of recipients.
Use the Default Mail Flow Policy settings to specify the maximum
number of recipients and the time interval that will be used by the other
mail flow policies by default. The time interval can only be specified
using the Default Mail Flow Policy.
number of recipients and the time interval that will be used by the other
mail flow policies by default. The time interval can only be specified
using the Default Mail Flow Policy.
Sender Rate Limit Exceeded
Error Code
Error Code
The SMTP code returned when an envelope exceeds the maximum
number of recipients for the time interval defined for this listener.
number of recipients for the time interval defined for this listener.
Sender Rate Limit Exceeded
Error Text
Error Text
The SMTP banner text returned when an envelope sender exceeds the
maximum number of recipients for the time interval defined for this
listener.
maximum number of recipients for the time interval defined for this
listener.
Exceptions
If you want certain envelope senders to be exempt from the defined rate
limit, select an address list that contains the envelope senders. See
limit, select an address list that contains the envelope senders. See
for more information.
Flow Control
Use SenderBase for Flow
Control
Control
Enable “look ups” to the SenderBase Reputation Service for this
listener.
listener.
Group by Similarity of IP
Addresses: (significant bits
0-32)
Addresses: (significant bits
0-32)
Used to track and rate limit incoming mail on a per-IP address basis
while managing entries in a listener’s Host Access Table (HAT) in large
CIDR blocks. You define a range of significant bits (from 0 to 32) by
which to group similar IP addresses for the purposes of rate limiting,
while still maintaining an individual counter for each IP address within
that range. Requires “Use SenderBase” to be disabled. For more
information about HAT significant bits, see “HAT Significant Bits
Feature” in the “Configuring Routing and Delivery Features” chapter.
while managing entries in a listener’s Host Access Table (HAT) in large
CIDR blocks. You define a range of significant bits (from 0 to 32) by
which to group similar IP addresses for the purposes of rate limiting,
while still maintaining an individual counter for each IP address within
that range. Requires “Use SenderBase” to be disabled. For more
information about HAT significant bits, see “HAT Significant Bits
Feature” in the “Configuring Routing and Delivery Features” chapter.
Directory Harvest Attack Prevention (DHAP)
Directory Harvest Attack
Prevention: Maximum
Invalid Recipients Per Hour
Prevention: Maximum
Invalid Recipients Per Hour
The maximum number of invalid recipients per hour this listener will
receive from a remote host. This threshold represents the total number
of RAT rejections and SMTP call-ahead server rejections combined
with the total number of messages to invalid LDAP recipients dropped
in the SMTP conversation or bounced in the work queue (as configured
in the LDAP accept settings on the associated listener). For more
information on configuring DHAP for LDAP accept queries, see the
“LDAP Queries” chapter.
receive from a remote host. This threshold represents the total number
of RAT rejections and SMTP call-ahead server rejections combined
with the total number of messages to invalid LDAP recipients dropped
in the SMTP conversation or bounced in the work queue (as configured
in the LDAP accept settings on the associated listener). For more
information on configuring DHAP for LDAP accept queries, see the
“LDAP Queries” chapter.
Table 7-8
Mail Flow Policy Parameters (continued)
Parameter
Description