This extension achieves all that it says, and works perfectly; from detecting signup pages to syncing with the dashboard (as well as the ability to label accounts).

There is however a very small issue in terms of ease of use, that would be auto filling previously used alias' from the popup menu created by the extension. There is only an option to "Create a new alias", and adding a list of previously created alias' would be helpful. This is a minor issue, and not something that affects the performance of the service itself.

In addition, another feature for the future could be the possibility of listing all the websites the email is used on.

Keep up the great work! I'm always hyped when Mozilla releases a new service because it never disappoints.