Yes, I'm sure walking your accounting department through how to use the command-line FTP tool in Windows is going to work out fantastically well.
Versus drag and drop file to this page. There you go. It's uploading.
That's why I said Dropbox or a Dropbox-like service, of which there are hundreds. Microsoft SharePoint is but one example.
Not that shell. The UI shell. Explorer. You can browse FTP sites just like network file systems, including drag and drop.
Go to Start->Run.
Type ftp://ftp-site/path/to/file. Drag and drop to your hearts content.
Windows explorer has FTP built into the shell. As does every other desktop OS.
If you care about file integrity, you want to out of band to verify the signatures on the binary anyway.
Dropbox is blocked in most commercial networks and offers no assurance of anything.