User Guide

Contents
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AsyncOS 9.1.2 for Cisco Email Security Appliances User Guide
Domain-Based Limits 4-11
Domain-Based Routing 4-11
Global Unsubscribe 4-11
Bounce Limits 4-12
CHAPTER 5 Configuring the Gateway to Receive Email 5-1
Overview of Configuring the Gateway to Receive Email 5-1
Working with Listeners 5-2
Configuring Global Settings for Listeners 5-6
Settings for Messages Containing Multiple Encodings: localeconfig 5-8
Listening for Connection Requests by Creating a Listener via the GUI 5-8
Partial Domains, Default Domains, and Malformed MAIL FROMs 5-12
Listening for Connection Requests by Creating a Listener via the CLI 5-13
Advanced HAT Parameters 5-14
Enterprise Gateway Configuration 5-15
CHAPTER 6 Sender Reputation Filtering 6-1
Overview of Sender Reputation Filtering 6-1
SenderBase Reputation Service 6-1
SenderBase Reputation Score (SBRS) 6-2
How SenderBase Reputation Filters Work 6-3
Recommended Settings for Different Sender Reputation Filtering Approaches 6-4
Editing Sender Reputation Filtering Score Thresholds for a Listener 6-5
Testing Sender Reputation Filtering Using the SBRS 6-6
Monitoring the Status of the SenderBase Reputation Service 6-7
Entering Low SBRS Scores in the Message Subject 6-7
CHAPTER 7 Defining Which Hosts Are Allowed to Connect Using the Host Access Table (HAT) 7-1
Overview of Defining Which Hosts Are Allowed to Connect 7-1
Default HAT Entries 7-2
Defining Remote Hosts into Sender Groups 7-3
Sender Group Syntax 7-4
Sender Groups Defined by Network Owners, Domains, and IP Addresses 7-4
Defining Sender Groups by SenderBase Reputation Score 7-6
Sender Groups Defined by Querying DNS Lists 7-7
Defining Access Rules for Email Senders Using Mail Flow Policies 7-8
HAT Variable Syntax 7-9
Understanding Predefined Sender Groups and Mail Flow Policies 7-11