The TaifunFile.List method only lists the file names (including path) of a folder if this folder and/or the non-media files contained therein can be accessed. If the files themselves are to be attached to an e-mail, they must first be zipped and then attached (if a certain size limit is observed).
For access rights (Android 11+) see here:
So show the folder (path) and how many files and file types are there. Also show the size of these files. As far as media files are concerned, these are hardly compressible. You only have access to non-media files on Android 11+ if the files were created by the app itself. Otherwise you have to use SAF.