I installed it and see what you mean. After the user submitted the page for email their is an iframe inserted into that box with this code.
As well as an ad.
On top of the ads that benefit the plugin author the email generated does not point to the post that you emailed about, It contains links like these two.
I know this is software as a service but that really seems to be a bit much. All this plugin does is provide a popup link for emailing people about a post. That email doesn't contain much and that tracking and ads are IMHO over the top.