I have to transmit flat files (1KB up to 5MB) with the BizTalk directly from receive port to a send port. There is nothing to do with the content of the file(s). Only a controlled transfer.
My question: How to do and is it really necessary to transform the file content into a XML message?
No, you don’t need to transform to XML if you don’t need/want to. Just use a passthrough pipeline (i.e. one without an assembler/disassembler) on your receive location and send port.