Problem: Large files routing in BizTalk
1) Create a WCF LOB Adapter/extend the SDK File adapter to implement file system watcher to monitor for files in a folder.
2) Once the file is created in the folder, create a new message containing the full path of the file and drop into message box via a custom receive pipeline component which promotes the absolute path of the file (c:\In\LargeFileName.xyz)
3) Create a custom send pipeline component which creates a new message and we associate the messageBody property to the file (available in the context) using file stream (c:\In\LargeFileName.xyz)
4) Create a send port with the message type filter subscribing to the message created in step 2 and use the send pipeline component created in step 3.