Hi wolfgang8741, thank you for the kind review and the feedback. For the subdomain aliases, they're really great because they're is no need to have the add-on actually generate them, you can easily create them on the fly. For example if you're on your favorite music streaming site you can just type in for the email music@yoursubdomain.mozmail.com and emails will start flowing through to that alias. Or if you're on a news site you could do newssite@yoursubdomain.mozmail.com. We created the subdomain feature for convenience in creating an alias, especially in person or when you're on a mobile app and don't have easy access to the add-on. We do encourage you to use random generated aliases as much as you can though, as a randomly generated alias has a lot more privacy benefits. Thank you!