When defining a file mask for a specific extension for a file receive location on BizTalk, there’s a difference in which files will be processed depending on the installed OS.
For example, a file receive location on BizTalk 2010 in Windows 7 with extension *.xls will not only process xls files but also xlsx files. While the exact same file mask defined on a receive location in Windows Server 2008 R2 will only pickup files with extension xls.
This behaviour is caused by the Windows operating system and can be reproduced without BizTalk in a command prompt.
Create 2 files in a folder location: one with extension txt the other with extension txt1. When you type ‘DIR *.txt’ in the command prompt on Windows 7, 2 files will be found. When doing the same on Windows Server 2008 R2, only 1 file will be found.