There are several options for holding online discussions at Cornell, both real-time and asynchronous. Many of these make it possible to save participants' comments for later reference, and all can save the time it takes to attend an in-person meeting.
Eliminate the difficulties that come with emailing files and reviews back and forth by using a dedicated sharing service. Keep your files in a central place so it's always clear which one is the latest version. Commenting features make it possible to see the conversation in context, and working with a centrally stored document reduces inbox clutter.