Confirm-Address is Thunderbird extension that shows the confirm-address dialog when you send the mail. And, at first, if you register YOUR DOMAIN (ex."mycompany.com"), you will see confirm-address dialog with highlight mail address when you send mail to other domain. And so, you can raise awareness of security and information leak. How to Install in Thunderbird: 1. Right-click the link below and choose "Save Link As..." to download and...