You could just split the file using a utility like 7-zip or something similar. Using 7-zip, you can zip-compress the .story file (optional) and then Split it using the file menu. Specify how big you want to individual pieces to be. It will result a list of files ending in .001, .002, etc. These can be sent individually. To reassemble them, you can use Join (file menu in 7-zip), or even use the command line in Windows (for example BigFile.zip becomes BigFile.zip.001, BigFile.zip.002, etc. This will reassemble them in their current folder: copy /b BigFile.zip.* BigFile.zip). Unzip the file using Windows or whatever.
