Mail Receiver Adpter - server not responding OK to MAIL FROM; 530 5.7.1 Client was not authenticated

Hi Experts,

I am facing following issue in Mail Receiver Adapter,

Delivery of the message to the application using connection Mail_http://sap.com/xi/XI/System failed, due to: com.sap.engine.interfaces.messaging.api.exception.MessagingException: com.sap.aii.af.sdk.xi.srt.BubbleException: Failed to call the endpoint [null "null"]; nested exception caused by: java.io.IOException: server not responding OK to MAIL FROM; 530 5.7.1 Client was not authenticated

Please help.

Regards,

Nitin Patil