User Guide

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AsyncOS 9.1.2 for Cisco Email Security Appliances User Guide
Chapter 24 Configuring Routing and Delivery Features
Controlling Email Delivery Using Destination Controls
You can define any of the following parameters for a domain in the configuration file. All parameters are
required for the
[DEFAULT] section except for the bounce_profile parameter:
Table 24-9 Destination Control Configuration File Parameters
Parameter Name Description
ip_sort_pref Specifies the Internet Protocol version for the domain.
Enter one of the following values:
• PREFER_V6 for “IPv6 Preferred”
• REQUIRE_v6 for “IPv6 Required”
• PREFER_V4 for “IPv4 Preferred”
• REQUIRE_v4 for “IPv4 Required”
max_host_concurrency The maximum number of outbound connections that will
be made by the appliance to a given host.
If you define this parameter for a domain, the
limit_type
and
limit_apply parameters must also be defined.
max_messages_per_connection The maximum number of messages allowed for a single
outbound connection from the appliance to a given host
before initiating a new connection.
recipient_minutes The period of time — between 1 and 60 minutes — that the
appliance will count the number of recipients. Leave
undefined if no recipient limit should be applied.
recipient_limit The maximum number of recipients allowed within the
given period of time. Leave undefined if no recipient limit
should be applied.
If you define this parameter for a domain, the
recipient_minutes, limit_type, and limit_apply
parameters must also be defined.
limit_type Specifies whether the limit will be applied to the entire
domain or to each mail exchange IP address specified for
that domain.
Enter one of the following values:
• 0 (or host) for the domain
• 1 (or MXIP) for the mail exchange IP address
limit_apply Specifies whether the limit will be applied system-wide or
for each Virtual Gateway address.
Enter one of the following values:
• 0 (or system) for system-wide
• 1 (or VG) for Virtual Gateway
bounce_validation Specifies whether to turn on bounce validation address
tagging.
Enter one of the following values:
• 0 (or off)
• 1 (or on)