I want another company to put a file into an IFS folder but each time we try they get an error message that the folder does not exist or not authorized. Any ideas why?
If you use FTP and the naming format is set to library/file rather than IFS you would see that error. Set the naming format using the following line in the FTP script:

quote site namefmt 1
cd /mydirectory

This was first published in September 2008