General questions about Relay email domains

Firefox Relay Firefox Relay Created: 05/11/2023 22% of users voted this helpful

How many unique Relay email domains can I create with my Premium account?

You can only register one domain with your account. Changing your unique domain name is not possible once you have set one. For details, visit Register your own domain with Firefox Relay Premium .

What is the difference between a random email mask and a custom email domain mask?

Custom domain email masks work a little differently than regular email masks. You don’t need to use the Generate a new mask option on the Relay dashboard when using a custom Relay email domain. You just provide an email address, and it will instantly be generated when you share it with a service or website. For example, if you are signing up for a newsletter, you could enter, and that email mask will instantly be created and added to your Dashboard. This even works when you are away from your computer, out shopping for instance. You can verbally provide, and it will instantly be generated and added to your dashboard when an email is sent to it.

Do I have to generate a custom mask on my Relay dashboard before using it at an establishment?

You don't need to generate a custom mask before you can use it. When you visit a store or a website, you just need to provide whatever email username that comes to your mind accompanied by your Relay email handler (like, and as soon as someone sends an email to a mask that belongs to your unique domain, it will be automatically generated in your dashboard.

Can I manually create a custom domain mask?

You can generate a custom domain mask from your dashboard by clicking on Generate new mask and then selecting your domain from the menu. General questions about Relay email domains

Is there a character limit for my custom domain name?

Your domain name can be up to 63 characters long.

What characters can I use to create a Relay email domain?

You can only use lower-case English letters, numbers, and hyphens to create a Relay email domain.

Is there a time limit for replying to an email that came through one of my masks?

You can only reply to an email within three months of receiving that email. Any replies outside this window will not be delivered.

Why won’t a site accept my unique email mask?

Occasionally, some sites may not accept an email address that includes a subdomain, which we call Relay email domains (, and others may not even accept addresses that are not from known email providers like Gmail, Hotmail, or Yahoo. If you encounter this problem, please report it to us by following the steps in this article.

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