Currently no delivery to &, as recipient cannot be reached

What causes this issue?

The message was processed correctly in the SAP system. However, a
subsequent system registers that the receiver &V1& cannot currently be
reached.


Information from external system (if available)
&V2&
&V4&&V3&

How to fix this error?

If you send the message again at a later time then it is possible that
it can be delivered successfully.

Error message extract from SAP system. Copyright SAP SE.