You can attach the MIDI files to your email and send through to the respective recipients. If you are sending a number of files it may be better to move them to a folder, zip this folder and send the zipped MIDI folder. This depends on how big the folder is. I'd say if it is smaller than 5MB then it will be fine to email the MIDI folder.
If the files are quite big you could upload them to media share site like [url]http://www.mediafire.com[/url] and then send the link through to the people you want to share the files with. YouSendIt also works well.