Can you please help us to resolve the error i banging my head from two weeks not able to find the root cause and we have outbound message it will fire every one hour if criteria meets. the problem was outbound message not sending the Ack message .when we check the outbound monitoring status Delivery failure status displaying as "Soap resoponse was Nack".does have any solutions to resolve this
I found a doc relevant to your problem:
Description of the issue:
As a result of a workflow rule, an outbound message was triggered and send to the configured endpoint but Salesforce failed to send it and the "Delivery Failure Reason" under Setup | Monitoring | Outbound messages shows "SOAP response was a nack". What's the meaning of this message?
Salesforce expects the configured endpoint for the outbound message to acknowledge (e.g. to return an "ack" for) the outbound message. However there are cases where the message is not acknowledged (e.g. the response is considered a "nack"). This could happen if the target endpoint is too busy to accept the request, or it accepts it but it does not send and ack back to Salesforce.
To determine the specific reason that caused the "nack", the server handling the outbound message on the configured target endpoint should be checked to ensure it sends an "ack" back to Salesforce and that it's dimensioned to handle the load accordingly.
There are tools like Soap UI by which you can check that you are getting response from the configured endpoint properly or not.
Outbound messages need an acknowledgement from the endpoint you fire. That acknowledgement is nothing but a soap message with an ack field returning true.
<?xml version="1.0" encoding="UTF-8"?> <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <soapenv:Body> <element name="notificationsResponse"> <Ack>true</Ack> </element> </soapenv:Body> </soapenv:Envelope>
You have to ask your endpoint developer to send the above soap message.(Or just above raw XML) it should be enough for SF to accept that outbound message was successful/