ESA FAQ: How can I alter the maximum message size for inbound mail?

Introduction

This document describes the process that is used in order to alter the maximum message size for inbound mail on the Cisco Email Security Appliance (ESA).

How can I alter the maximum message size for inbound mail?

The default maximum message size for inbound mail is 10mb for most mail flow policies. The Trusted mail flow policy is set at 100mb. The maximum message size includes the message body and any attachments.

Note: The mail flow policies, such as the HAT Overview, are specific to a listener. If you have multiple listeners, you must ensure that you choose the correct listener. For example, if you want to modify the maximum message size for inbound mail, navigate to Mail Policies > Mail Flow Policies and choose the Inbound listener.

The default policy applies to outbound mail if you have a single listener configured for both the Inbound and Outbound listeners. If you have separate listeners configured for the Inbound and Outbound email, then the default settings are different for both listeners and must be configured independently.

Complete these steps in order to change the maximum message size to a company policy of 20mb for inbound mail:

1. Navigate to Mail Policies > Mail Flow Policies.
   
   
2. Click Default Policy Parameters.
   
   
3. Locate the Max. Message Size: field and change the custom value to 20M.
   
   
4. Click Submit.
   
   
5. Click Commit changes.
   
   

Note: In the Mail Flow Policies section, you can click Accepted, Throttled, Blocked, and Trusted in order to enter a custom value, if desired.