Rated 5 out of 5 stars

Useful, but may I suggest using decodeURI() to parse the addresses? The name of my recipients are not always in ASCII characters so a long list of URI escape sequences do not help. Something like:
// Arguments
URL = decodeURI(document.URL);
console.log(URL);
addresses = URL;

This review is for a previous version of the add-on (3.8).