How to get the HTTP Header of an outbound integration message

Summary:

Destination system claims that user credentials are missing in the OTM outbound message. How to get the HTTP Header of an outbound integration message to make sure user credentials are there.

Content (required):

[Background]

Our OTM Outbound Integration is via httppost and basic authentication. We understand there is a change lately in outbound integration for HTTP Authentication (Basic). User Name and Password are no longer in Transmission Header. Instead, they are in HTTP Header under "Authorization".

[Issue]

People working on the destination system claimed that they received the http message without "Authorization" info in header.

[Question]

Is there a way in OTM to check the outbound http header?