SAP Message SALERT066 - No response from HTTP destination &

Diagnosis
The receiving system has not sent confirmation.
The receiving system is able to send confirmation that it has receivedan alert. This confirmation must be in a defined XML format. Theconfirmation is optional.

Procedure
If no confirmation is to be sent, ignore this message. If one is to besent, check whether the receiving system is available. Use transactionSM59 to test the connection.