Cisco Cisco Email Security Appliance C170 Guia Do Utilizador
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Cisco AsyncOS 9.1 for Email User Guide
Chapter 24 Configuring Routing and Delivery Features
Directing Bounced Email
Example Bounce Profiles
Consider these two examples using different bounce profile parameters:
In Example 1, the first recipient delivery attempt is made at t=0, immediately after the message is
injected into the appliance. With the default initial retry time of 60 seconds, the first retry attempt is
made approximately one minute later at t=60. The retry interval is calculated and it is determined to use
the maximum retry interval of 60 seconds. Thus, the second retry attempt is made at approximately
t=120. Immediately after this retry attempt, the system generates a hard bounce message for that
recipient because the maximum number of retries is two.
injected into the appliance. With the default initial retry time of 60 seconds, the first retry attempt is
made approximately one minute later at t=60. The retry interval is calculated and it is determined to use
the maximum retry interval of 60 seconds. Thus, the second retry attempt is made at approximately
t=120. Immediately after this retry attempt, the system generates a hard bounce message for that
recipient because the maximum number of retries is two.
In Example 2, the first delivery attempt is made at t=0 and the first retry is made at t=60. The system
hard bounces the message immediately before the next delivery attempt (scheduled to occur at t=120)
because it has exceeded the maximum time in queue of 100 seconds.
hard bounces the message immediately before the next delivery attempt (scheduled to occur at t=120)
because it has exceeded the maximum time in queue of 100 seconds.
Delivery Status Notification Format
Bounce messages generated by the system, by default, use the Delivery Status Notification (DSN) format
for both hard and soft bounces. DSN is a format defined by RFC 1894 (see
for both hard and soft bounces. DSN is a format defined by RFC 1894 (see
http://www.faqs.org/rfcs/rfc1894.html
) that “defines a MIME content-type that may be used by a
message transfer agent (MTA) or electronic mail gateway to report the result of an attempt to deliver a
message to one or more recipients.” By default, the delivery status notification includes an explanation
of the delivery status and the original message if the message size is less than 10k. If the message size
is greater than 10k, the delivery status notification includes the message headers only. If the message
headers exceed 10k, the delivery status notification truncates the headers. If you want include messages
(or message headers) that are greater than 10k in the DSN, you can use the
message to one or more recipients.” By default, the delivery status notification includes an explanation
of the delivery status and the original message if the message size is less than 10k. If the message size
is greater than 10k, the delivery status notification includes the message headers only. If the message
headers exceed 10k, the delivery status notification truncates the headers. If you want include messages
(or message headers) that are greater than 10k in the DSN, you can use the
max_bounce_copy
parameter
in the
bounceconfig
command (this parameter is only available from the CLI).
Table 24-6
Example 1: Bounce Profile Parameters
Parameter
Value
Max number of retries
2
Max number of seconds in queue
259,200 seconds (72 hours)
Initial number of seconds before retrying
60 seconds
Max number of seconds to wait before retrying
60 seconds
Table 24-7
Example 2: Bounce Profile Parameters
Parameter
Value
Max number of retries
100
Max number of seconds in queue
100 seconds
Initial number of seconds before retrying
60 seconds
Max number of seconds to wait before retrying
120 seconds