Cisco Cisco Email Security Appliance X1050 Guía Para Resolver Problemas

is added to the Envelope Sender as it is sent by your appliance. If the message bounces, the Envelope
Recipient address in the bounce typically includes the bounce verification tag.

Note: Refer to the Configuring Bounce Verification Address Tagging Keys section of the Advanced User
Guide for additional details.

You can enable or disable bounce verification tagging system−wide as a default. You can also enable or
disable bounce verification tagging for specific domains. In most situations, you enable it by default, and then
list specific domains for exclusion in the Destination Controls table.

When a Content Security appliance delivers a bounce message that already contains a tagged address to
another Content Security appliance inside the De−Militarized Zone (DMZ), then AsyncOS does not add
another tag.

Caution: If you enable bounce verification, it might cause your appliances to reject legitimate mail that is sent
with a blank Envelope Sender.

Complete these steps in order to configure bounce verification on the ESA:

Navigate to Mail Policies > Bounce Verification and enter a tagging key manually with a random
selection of numbers and letters, such as 4r5t6y7u.

1. 

Edit the bounce verification settings:

Navigate to Mail Policies > Destination Controls and enable bounce verification.

A. 

Choose Default from the Domain field (or your custom destination).

B. 

Once the Default window opens and the Bounce Verification section appears, click Yes.

C. 

2. 

Ensure that untagged (misdirected) bounces are blocked:

Navigate to Mail Policies > Mail Flow Policies.

A. 

Select the appropriate policy and locate the Security Features section.

B. 

Ensure that the Evaluate Untagged Bounces value is set to No. On earlier versions of
AsyncOS, the Accept Untagged Bounces value should be set to No.

C. 

3. 

Updated: Jul 11, 2014

Document ID: 117918