When Dead Letter Channel is doing redelivery it is possible to configure a Processor that is executed just before every redelivery attempt. This can be used for the situations where you need to alter the message before it is redelivered. See below for sample.
We also support for per onException to set a onRedeliver. That means you can do special on redelivery for different exceptions, as opposed to onRedelivery set on Dead Letter Channel can be viewed as a global scope.