Cisco Cisco Email Security Appliance C170 Guia Do Utilizador

AsyncOS also includes a HAT setting related to IronPort Bounce Verification for 
considering whether untagged bounces are valid. The default setting is “No,” 
which means that untagged bounces are considered invalid and the appliance 
either rejects the message or applies a customer header, depending on the action 
selected on the Mail Policies > Bounce Verification page. If you select “Yes,” the 
appliance considers untagged bounces to be valid and accepts them. This may be 
used in the following scenario:

Suppose you have a user that wants to send email to a mailing list. However, the 
mailing list accepts messages only from a fixed set of Envelope Senders. In such 
a case, tagged messages from your user will not be accepted (as the tag changes 
regularly).

To help that user, follow these steps:

Add the domain to which the user is trying to send mail to the Destination 
Controls table and disable tagging for that domain. At this point, the user can send 
mail without problems.

However, to properly support receiving bounces from that domain (since they will 
not be tagged) you can create a sender group for that domain and enable the 
Consider Untagged Bounces to be Valid parameter in an “Accept” mail flow 
policy: