I am having trouble emailing one of my show files to someone
The internet wasn't designed to send files, just messages. So attaching a file to an email message can easily be a mess.
The Mac and Windows versions of Lightwright use EXACTLY the same format for show files - there is no need for any kind of translation or anything.
The Windows version of Lightwright requires .LW4 to be at the end of the filename, and the Mac OSX version needs it, too, although you may not see it.
If you've gotten around that, then the most likely problem is the internet. There are no straightforward answers, because the internet was designed to send email text messages, not data file attachments.
The best way to ensure that your show file will be sent successfully is to compress it before attaching it to your email message. Windows users can use WinZip to .zip versions of their show files, which can then usually be sent successfully attached to email messages. Macintosh users can use either .zip or Stuffit to create both .zip and .sit versions, which can also be attached to email. Be sure the person on the receiving end can un-zip or un-stuff your attachment!
If you've tried all of this, then I recommend Fedex.
Good luck!