Currently no delivery to &, as no route known

What causes this issue?

The message could not be delivered to recipient &V1&, since no route for
this was found.

System Response

Processing was completed normally.
Additional information of the used node (if available, in the system
language of the node, may contain address recommendation):
&V4&

How to fix this error?

Attempt to resend the message at a later time.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.