Checking for duplicate files before processing

Hi All,

We have several BizTalk 2006 applications. The one in question polls a directory for a file and when it sees a file it picks it up, converts it from XML to a flat TXT file and copies it to another directory.

We had an incident recently where the system feeding that file to BizTalk created a duplicate, which BizTalk picked up and processed, causing some duplication issues in the destination system.

Quite simply I would like to use BizTalk to check the file name before it copies the file, and if its file name contains the same date as a file it has already copied that day (should only ever be 1 file per day), through an error/mail and move it somewhere else so the destination system doesn't try processing it.

I appreciate most of this work should be done by both the feed and destination systems, but for various reasons - including timing, this isn't currently an option.

Any advice on a direction I can go with this would be gratefully received.

I have access to the visual studio project and the BizTalk 2006 server console, so I can in theory add any changes that way.

Thanks!