It is strongly suggested that you do not disable NDR responses on any mail server. However, it is possible to disable NDR responses in Postfix if you would like to.
Open your Postfix master.cf file and find the following line:
bounce unix - - n - 0 bounce
Change it to this:
bounce unix - - n - 0 discard
Next, restart Postfix.
Please be advised that you will see an error in your logs whenever Postfix runs the discard handler instead of the bounce handler. The errors will look similar to this:
Dec 15 16:07:40 websrv1 postfix/discard[15220]: warning: unexpected attribute nrequest from bounce socket (expecting: flags)
Dec 15 16:07:40 websrv1 postfix/discard[15220]: warning: deliver_request_get: error receiving common attributes
Article ID: 119, Created: 4/23/2025 at 4:01 PM, Modified: 4/23/2025 at 4:01 PM