Hi donniebnyc. Thank you for giving the extensions a try. To make it work, please make sure you test it on non-Mozilla websites (some Mozilla websites block add-ons for security reasons), and that you have an email client assigned with mailto: links. You can try that second on my personal website https://michal.stanke.cz/ by clicking my email link in the very bottom.

EDIT: Hi donniebnyc. It might have happened when you use Gmail or any other webmail service. This is now fixed in 1.2.1.