Steps to reproduce:
-Click on "Share page by email"
Fill in the "To" field. Press the "Share" you will see that the js modal is simply being reset, with no error or confirmation message. NOTE: no error stack trace is displayed, meaning the mailer plugin was not called.
If instead of pressing the "Share" button you press "Return", you wil lbe redirected to a page and get the normal error/confirmation.
So it means that the "Share" button is not working right on IE's.