Suvadeep,
You have to check in 2 places in the TN DocumentType IdentifyingQueries for ReceiverID(set the xpath that will extract the id from the document select DUNS or Userdefined etc…based on the partner profile you have in place),check ProcessingRule criteria for the sender/receiver/documentType are set properly and note this rule should be above the default rule.
Make sure the above conditions satisfy and get your document successfully recognized in TN.
HTH,
RMG
#B2B-Integration#Integration-Server-and-ESB#webMethods