An e-mail mask is a forwarding address that you use when you want to keep your real e-mail address private. All emails that are sent to your email mask will be forwarded to your real email address without revealing it.
With Firefox Relay, you can create up to 5 different masks to use and reuse on websites where you register. All emails sent to your masks from those websites will be forwarded to your real email. This is a preference that you can change from the Firefox Relay dashboard. You can manage all the masks you have created and decide from which ones you want to receive forwarded emails.
A subscription to Firefox Relay Premium lets you create an unlimited number of masks to use. You will also be able to reply from your real email to emails that have been forwarded to you. To learn more about the benefits of Firefox Relay Premium, visit Subscribe to Firefox Relay Premium.