Maski vs Firefox Relay: generous until you need to answer someone

Fifty free masks. Not ten, not five. Mozilla gives away more free addresses than anyone else here, their code is under a public licence, and the organisation has spent twenty years not selling you out. If you are choosing on free tier alone, stop reading and go sign up.

The reason I still built Maski is that the free tier is shaped around receiving mail, and about half of what I need an alias for involves sending it.

Two different bets about what a free plan is for

Relay’s free plan is a wide, shallow offer. Fifty masks, per Mozilla’s own terms, and mail forwards through all of them. What it does not include is replying. Their plan matrix lists replying as not included on the free tier, which means a free mask is an inbound pipe and nothing else.

Maski’s free plan is narrow and deep. 10 aliases, but the per-sender rules, the block list and the one-click pause all work on the free plan, because those are the things that decide whether an address stays usable.

Neither shape is wrong. They answer different questions. Relay is answering how many throwaway addresses can I have, and Maski is answering how much control do I have over the ones I actually use.

What matters, side by side

Maski compared with Firefox Relay on price, aliases included, custom domains, replying to a forwarded message, and sending a new message from the alias.
Compared on	Maski	Firefox Relay
Price	Free, or $4.99 a month for Pro Buys the alias service itself. No mailbox or storage is bundled in. Pro is free for a year for the first 1,000 sign-ups.	Free, or 1.99 a month for Premium in the visitor's local currency Buys the mask service. The price is not on the page; it comes from Relay's own config endpoint. Not sold in every country. Relay's pricing endpoint — Firefox Relay, opens in a new tab Premium — Firefox Relay, opens in a new tab
Aliases included	10 on Free, 25 on Pro	50 masks on the free plan, unlimited on Premium Mozilla's terms state 50. The marketing page ships a stale 5 and shows 50 once it loads. Subscription terms — Firefox Relay, opens in a new tab Premium — Firefox Relay, opens in a new tab
Custom domains	Yes, on Pro Bring your own domain. Maski can publish the DNS records for supported providers.	Not your own domain — one label under Mozilla's mozmail.com, on Premium anything@yourlabel.mozmail.com. One per account, and unchangeable once set. Relay domains — Firefox Relay, opens in a new tab
Reply to a forwarded message	Yes, on Pro The alias stays in the From address. Your real address is never disclosed to the sender.	Premium only, within three months of the message Not included on the free plan. Within three months of the message. Premium — Firefox Relay, opens in a new tab FAQ — Firefox Relay, opens in a new tab
Send a new message from the alias	Yes, on Pro You compose in your own mail client and address the message through Maski, so the alias is the sender.	Not stated Relay's pages do not state either way whether a new message can be started from a mask. Their terms rule the equivalent out for text messages and say nothing about email, so we do not read that silence as an answer.

Verified 11 September 2026. I re-check every figure on its source page, and this date only moves when the whole table has been checked again.

A mask you cannot reply from is a mask you use once

Think about where you actually hand out an address. A shop, a landlord, a recruiter, a marketplace buyer. In at least half of those the other side is going to ask you a question, and you are going to have to answer it from the address they have.

On free Relay you cannot. You go to Premium or you go back to your real address, which undoes the entire point of having used a mask in the first place.

Premium does support replying, within three months of receiving the message. That window is fine for most things and worth knowing about for the rest.

Their custom domain is not your domain

Relay Premium includes what the marketing calls a custom domain. It is a label you choose underneath Mozilla’s mozmail.com, so you end up at anything@yourlabel.mozmail.com. You pick the label. Mozilla owns the domain.

Mozilla is also clear that you get one, and cannot change it once it is set. One shot, permanent.

That matters for the thing nobody thinks about until they need it, which is leaving. Addresses on a domain you own move with you to any provider. Addresses on mozmail.com do not move anywhere, ever. Maski’s custom domains are domains you registered and control, and if you walk away from Maski the addresses keep working somewhere else.

You may not be able to buy Premium at all

Relay Premium is sold in a specific list of countries. From plenty of places, including India, the paid columns on their pricing page do not offer you a purchase button. They offer a waitlist.

So for a large part of the world the comparison is not free Relay against paid Maski. It is free Relay, permanently, against whatever else you can actually buy.

BE HONEST: when Firefox Relay is the right call

Fifty free masks beats 10. It is not close. If you want a large pile of disposable addresses for signups you will never reply to, Relay is the better free tier and I am not going to pretend my number is bigger.

Mozilla’s code is public. Mine is not.Relay is published under the Mozilla Public License and the repository is linked from Mozilla’s own terms of service, which is a stronger commitment than a footer link. The Maski repository is private. If auditability is your deciding factor, the decision is already made.

It is already in your browser. If you use Firefox, mask creation is right there at the signup form with no extension to install and no second account to keep.

Unlimited masks on Premium. Relay lifts the cap entirely once you pay, and Maski keeps a number on both plans. If you want to stop counting addresses altogether, that is the plan that does it.

Is one of those the reason you would not switch?

Then tell me which one. If the thing keeping you on Firefox Relay is a feature I do not have yet, I would rather hear it from you than guess at it, and a short note saying what you need and what you are using it for is worth more to me than any amount of competitor research.

Write to jay@maski.dev and it comes to me. If you would rather it went to the support queue, use hey@maski.dev. I cannot promise to build everything, and I will not pretend otherwise, but nothing gets built that nobody asked for.

Keep Relay for signups. Try Maski for the ones that answer back.

These are not mutually exclusive and I would not pretend otherwise. Use Relay’s fifty for throwaway signups. Put a Maski alias on the handful where somebody is going to email you back and you will need to reply as that address.

Start free Read the other comparisons