DuckDuckGo Email Protection is the only genuinely unlimited free alias service, and it takes about two minutes to set up. Firefox Relay gives you 50 free masks, SimpleLogin and Proton Pass 10 each, addy.io 10 active shared-domain aliases, and Forward Email unlimited forwarding if you already own a domain. Every free tier has a real limit somewhere — the useful question is which limit you'll hit first.
Every free tier, side by side
| Service | Free allowance | Reply from alias? | Own domain? | The catch |
|---|---|---|---|---|
| DuckDuckGo Email Protection | Unlimited addresses + 1 personal @duck.com | ✓ | ✗ | No paid tier at all, so no custom domain path. Addresses are on DuckDuckGo's domain permanently. |
| Firefox Relay | 50 masks | ✗ (Premium only) | ✗ | 50 sounds generous until you use one per signup. Replies are paid. |
| SimpleLogin | 10 aliases, 1 mailbox | ✗ | ✗ | 10 is a trial, not a system. Custom domains are Premium at $36/yr. |
| Proton Pass | 10 aliases | ✗ | ✗ | Same 10-alias ceiling; it's the same alias engine as SimpleLogin. |
| addy.io | 10 active shared-domain aliases, 10MB/month | ✗ | ✗ | The bandwidth cap bites before the alias cap if any list sends images. |
| Forward Email | Unlimited aliases, unlimited domains, forwarding only | ✗ (send is $3/mo) | ✓ Required | Free only if you already own a domain. You can't use it without one. |
| 33Mail | Unlimited aliases, 10MB/month | ✗ | ✗ | 10MB a month is very tight. Replies and custom domains start at $1/mo. |
| Apple Hide My Email | None — requires iCloud+ | ✓ | ✗ | Not a free service. Listed because people assume it is. |
| Don't SPAM Me | Free software, unlimited aliases | ✗ Not yet | ✓ Required | Free only if you already own a domain, same as Forward Email. |
Which limit you hit first
Free tiers are not really priced in dollars. They're priced in the thing they run out of, and each service picked a different thing.
Alias count — SimpleLogin, Proton Pass, addy.io
Ten aliases is enough to try the idea and not enough to run it. The whole point of a unique address per service is that attribution works, and attribution needs coverage. With ten, you're choosing which ten companies you don't trust — which is a guess, and the guess is usually wrong, because the leak comes from the account you thought was boring.
These caps are set where they are deliberately. Ten is enough to feel the benefit and start noticing the ceiling.
Bandwidth — addy.io, 33Mail
10MB a month is the quietest limit on this list and the most surprising in practice. A single retailer's HTML newsletter with images runs to a few hundred kilobytes. Twenty of those a month and you're at the cap, with mail silently not arriving. Bandwidth caps punish exactly the use case aliases are for — newsletters and shopping accounts — so read them as much lower than they look.
Replies — nearly everyone
Only DuckDuckGo lets you reply from an alias for free. Everywhere else it's a paid feature, including for us: we don't support replying at all, on any tier. If you need two-way conversation through an alias — a marketplace listing, a landlord, a recruiter — free tiers are mostly not an option and you should read how reply support actually works before choosing.
Whose domain it is — all of them
This is the limit nobody lists because it doesn't look like one. Free aliases live on the provider's domain: @duck.com, @mozmail.com, @simplelogin.com. That's fine until the day you want to leave, at which point every address you've handed out has to be changed at every service using it.
It's also not purely hypothetical. In June 2026 Apple announced it would move Hide My Email addresses to a dedicated domain — a change that would have made every alias identifiable and blockable in one line of a signup filter — and reversed it ten weeks later after complaints. Users had no say in either direction. That's the property of renting a namespace.
So what should you actually do?
If you've never used aliases: DuckDuckGo
Free, unlimited, replies included, strips email trackers, no upsell, no card. There is no reason to start anywhere else. Spend a month finding out whether per-service addresses fit how you work before you spend anything — plenty of people try the idea and find it more admin than they want, and that's a genuinely useful thing to learn for free.
If you already own a domain: Forward Email or us
Both are free and both put aliases on a domain you own, which is the only configuration that survives you changing your mind about the provider. Forward Email is open source, has been running longer, and its free tier covers unlimited forwarding across unlimited domains. Ours adds per-alias spam attribution and leak alerts, and doesn't support replies. Pick on which of those you care about — and if you're weighing them, our side-by-side is honest about where they're ahead.
If you don't own a domain but want the portable version
Then "free" isn't the right frame, because the domain is the cost. A .com is roughly $10–15 a year at most registrars — less than every paid alias tier on this list except Firefox Relay's $11.88. If portability matters to you, buying the domain and using free software on top of it is cheaper than the subscriptions, not more expensive. If it doesn't matter to you, don't buy one; use DuckDuckGo and keep the money.
The honest summary
"Free email alias" splits into two genuinely different products that share a name. One is a provider-hosted address that costs nothing and can't move — good, useful, and the right answer for most people starting out. The other is free software over a domain you pay for, which costs about a dollar a month in registration and can move anywhere.
Nearly every article on this topic conflates them, usually because the author sells the second kind. We sell the second kind. If ten aliases on someone else's domain covers what you need, that is a complete answer and you should take it.
More: every service compared, paid tiers included · custom domain vs provider domain · how aliases work