What Is an Email Alias? Meaning, Types, Examples

An email alias, or alias email address, is an extra address that delivers mail to you, so you can give it out instead of your main address. The word covers two things people often mix up. One is a second address on the account you already have, such as an iCloud Mail alias or a Gmail plus address. The other is a separate address you give to one shop or service, to keep your main address out of its database.

For example, you sign up at a shop with shop-k7q2@example.com instead of jane@example.com. The shop’s mail still reaches you, you can see which address it came in on, and with a provider alias or a forwarding alias you can switch that one address off if it starts attracting spam. CatchNone is an app for the second kind: every shop and newsletter gets its own address, and each message shows which one it reached, on iPhone, iPad, and Mac.

How email aliases work: the five types

Every alias ends up in a mailbox you read. The types differ in how the mail gets there.

How the mail moves in each type:

Provider alias     sender → your mailbox
Plus address       sender → your mailbox (tag kept)
Forwarding alias   sender → alias service → your mailbox
Catch-all          sender → domain mailbox (or forwarded to one inbox)
Receive-and-read   sender → app's service or domain mailbox → alias app

Provider aliases

A provider alias is a second address on the same account. It shares your mailbox, password, and storage.

• iCloud Mail: up to three @icloud.com aliases (as of September 2026), which can send and receive. You add them at icloud.com/mail under Settings → Add Alias. Apple says they can’t be changed, transferred, or converted, and if you have three and delete one, you wait seven days before you can create another. Mail to an alias you turn off or delete is returned to the sender.
• Google Workspace: as of September 2026, an admin can add up to 30 aliases per user at no extra cost.
• Personal Gmail: Google says you may be able to change your @gmail.com address. The old one becomes an “alternate email,” and mail to both arrives in your inbox.
• Microsoft account (Outlook.com): Microsoft now calls an alias “another username.” You manage them at account.live.com/names/manage, and they all share a single password.
• Fastmail Masked Email: random, per-site addresses that land straight in your Fastmail mailbox, with no relay in between.

Plus addresses

Add a plus sign and a word before the @, and jane+shop@example.com lands in the inbox of jane@example.com. There’s nothing to set up. The practice is called subaddressing and is described in RFC 5233, but support is up to each provider. Gmail’s Help calls these “Gmail aliases,” and Microsoft turns them on by default in Exchange Online.

They’re good for filters and weak for privacy: anyone who sees one can delete the tag and get your real address, and some signup forms reject the + sign. The guide to plus addressing in Gmail, Outlook, and iCloud has the details.

Forwarding aliases

An alias service gives you a random address for each site and passes that site’s mail to your real inbox. The site sees only the alias. The service sees everything, because it handles every message.

Apple’s Hide My Email is part of paid iCloud+ and lets you create “as many addresses as you need.” On iPhone (iOS 26 and iOS 27), it’s in Settings → [your name] → iCloud → Hide My Email (Apple’s steps). SimpleLogin, Proton Pass, Firefox Relay, and addy.io have free plans with a set number of aliases (counts in the FAQ below), and DuckDuckGo Email Protection is free. How these compare with iCloud’s own aliases is covered in Hide My Email vs email aliases.

Catch-all addresses

If you own a domain, you can accept mail sent to any address on it, including ones you make up on the spot. Cloudflare Email Routing has a catch-all rule under Compute → Email Service → Email Routing → Routing Rules. It hosts no mailbox: it forwards everything to one inbox you choose, and inbound mail is unlimited on the Workers Free plan, as of September 2026. iCloud+ Custom Email Domain can also accept mail to addresses you haven’t set up.

The catch: you have a domain to renew, and mail to every typo or guessed address arrives too. The guide to catch-all email addresses and their risks covers both.

Receive-and-read alias inboxes

This model doesn’t forward alias mail into your main inbox. You read it in a separate app that labels every message with the address it reached. On the app’s own domain, its service receives the mail. On your own domain, your provider still delivers it to a mailbox you have and the app reads that inbox, so if it’s your main mailbox, the messages are there too. It’s receive-only by design: signup mail stays in its own app, and you reply from your usual account.

What are email aliases used for? Examples

Mostly three jobs: sorting mail, keeping your main address out of company databases, and giving a role or a business its own address.

• Newsletters: jane+news@example.com, with a filter that files everything sent to it in one folder.
• A small business: hello@example.com and billing@example.com as provider aliases on one person’s mailbox.
• An online shop: a random forwarding address. If spam starts arriving on it, you know which shop had that address, and you switch off that one address.
• Hotel Wi-Fi: hotel-lisbon@example.com, made up on the spot on a catch-all domain.

Alias vs email address vs a second account

Every alias is an email address, but it isn’t an account. An alias points at a mailbox you already have. A second account is a separate mailbox with its own password, storage, and recovery settings.

Providers draw the line differently. Google says Workspace aliases are not Google Accounts, so you can’t sign in with one. Microsoft lets you sign in with any alias on your account. Apple says you can’t use an iCloud alias to create a separate Apple Account.

If you want separation you can walk away from, with a different password and recovery phone, you need a second account. If you want more addresses without more logins, you want aliases.

Alias vs forwarding: what’s the difference?

Forwarding is a delivery method: mail sent to one address is sent on to another. An alias is an address. Many aliases work by forwarding, but provider aliases and plus addresses don’t; the mail lands in your mailbox.

In practice the difference shows up in two places. A forwarded message passes through a third party that can see it. And replying as the alias needs that service to relay your reply: SimpleLogin, for example, gives each contact a “reverse-alias.”

“Masked email” is a common name for a random, per-site alias. Mozilla calls Firefox Relay’s addresses “email masks,” and Masked Email is the name of Fastmail’s feature, whose addresses deliver straight into your Fastmail mailbox instead of forwarding. Hide My Email is Apple’s version: it forwards to your iCloud Mail address or another address on your Apple Account. When you use it through Sign in with Apple, the address forwards mail only from that app or website.

Plain forwarding, such as sending everything from an old mailbox on to a new one, isn’t an alias at all.

Can you send or reply from an email alias?

It depends on the kind. Provider aliases can usually send. Plus addresses usually can’t. Forwarding services mostly let you reply, often on paid plans only. As of September 2026:

Gmail’s “Send mail as” for third-party addresses ends in January 2027, and new setups may be restricted before then. Google Workspace aliases aren’t affected, but if you reply as your own domain from a personal Gmail account, plan another way to do it.

Can an email alias be traced back to you?

Not from the address alone, if the alias is random. But the site still has everything else you gave it, and an alias keeps your address from senders; it doesn’t make you untraceable. These are the ways one gets linked to you:

1. Everything else you give the site: your name, phone number, delivery address, and payment card tie the account to you whatever the address is.
2. Plus addresses: delete the tag and the real address is left.
3. Aliases on a personal domain or username subdomain: shop@jane.example.com and news@jane.example.com are plainly the same person, and so is any pair of addresses on a domain only you use. addy.io points this out for aliases under a username and offers random aliases on a shared domain instead.
4. The alias service: it keeps the link between the alias and your real address. Apple’s US Legal Process Guidelines say basic customer information for Hide My Email “can be obtained with a subpoena or greater legal process.”
5. What you add to a reply: Firefox Relay warns that adding a CC or BCC to a reply exposes your real address, and addy.io reminds you not to sign with your full name.
6. Bugs: a message sent to a Hide My Email address and rejected as spam could expose the person’s real address in the sender’s mail logs. It was reported to Apple in June 2025, and Apple says it was fully fixed in a patch on July 3, 2026.

Tracking is a separate question. An alias doesn’t stop a tracking pixel from reporting that you opened a message. Some apps and services help: CatchNone keeps remote images, including most tracking pixels, blocked until you load them, and DuckDuckGo and Firefox Relay strip trackers.

Are email aliases worth it?

For signups, shops, and newsletters, usually yes. They cost little or nothing, and they give you two things a single address can’t: you can see which company’s address started getting spam, which points to who leaked or sold it, and you can cut off one sender without changing your address everywhere. Addresses do leak: Have I Been Pwned lists more than 17 billion breached accounts across more than 1,000 breaches (September 2026).

What can go wrong:

• Some sites refuse them. Mozilla’s Firefox Relay FAQ says some sites won’t accept an address with a subdomain, and “others have stopped accepting all addresses except those from Gmail, Hotmail, or Yahoo accounts.” Users raised the same worry when Apple planned to move Hide My Email to a separate domain, and in August 2026 Apple kept it on icloud.com.
• The service can close. Skiff announced on February 9, 2024, that Notion had acquired it, and it shut down its services on August 9, 2024. Users who opted in kept forwarding until February 9, 2025. An address on someone else’s domain lasts as long as they keep it running. An address on a domain you own can move to a new host.
• Ending a paid plan changes what works. Some services keep aliases working, others deactivate some of them or stop replies, so check what yours does before you cancel.
• There’s more to keep track of. Note which address you used where, for example in your password manager.

Which kind to use depends on the job. For filtering, use a plus address; for a second public or role address, a provider alias; for a private address per signup, an alias inbox such as CatchNone or a forwarding alias; for any address on the spot, a catch-all on a domain you own. For a situation-by-situation answer, see how to hide your email address, and for the services side by side, email alias services compared.

Where not to use an alias

Use your real address, or one on a domain you’ll keep, for anything you’d need to recover an account or prove who you are: your bank, tax and government services, healthcare, and legal matters. Mozilla’s Relay FAQ gives the same advice and adds concert and flight boarding passes, and any mail whose attachments you must receive. And if your alias can’t reply, don’t use it where you’ll need a back-and-forth, such as with a landlord or on a job application.

The recovery address for your main account matters most. Google’s advice is to choose “an email address you use regularly but not the one you use to sign in to your Google Account.” If that address depends on an alias service you might stop paying for, you could lock yourself out.

CatchNone: an alias for every signup

CatchNone, the app behind this Journal, is a receive-and-read alias inbox, available for iPhone, iPad, and Mac. You create a named alias for each shop, newsletter, or account and read its mail in the app, where every message is badged with the alias it reached, so a leaked or sold address shows up. Messages open with remote images, including most tracking pixels, blocked until you load them.

With Premium, you get random @catchnone.com addresses, such as abcde-12345@catchnone.com, with no domain, DNS, or mailbox to set up. Switch one off and senders get a bounce. On a domain you already own, the Free plan includes up to 10 aliases, and Lite and Premium have no limit. The domain’s mail needs to reach a mailbox’s inbox, usually through a catch-all, and that mailbox must accept IMAP with a password or app password, or JMAP with an access token. The app reads that inbox read-only from your device, so the mail never passes through CatchNone’s servers. On your own domain, marking an alias as not in use is only a label; to block an address, use a rule at your mail provider.

CatchNone is receive-only by design: you answer from your usual mail account, which shows that address to whoever you reply to. CatchNone’s service keeps @catchnone.com mail for 30 days after it arrives. If Premium ends, mail to those addresses is deleted on arrival until you subscribe again and open the app; the addresses stay reserved. Keep bank and account-recovery mail on your real address or a domain you own.

FAQ

Are email aliases free?

Plus addresses cost nothing, and provider aliases come with your mail account at no extra cost. Creating Hide My Email addresses whenever you like needs a paid iCloud+ plan, but the Hide My Email option inside Sign in with Apple is available without one. CatchNone’s Free plan includes up to 10 aliases on a domain you own, and @catchnone.com addresses need Premium. DuckDuckGo Email Protection is free, and SimpleLogin, Proton Pass, Firefox Relay, and addy.io have free plans; Fastmail has none. A catch-all costs a yearly domain renewal, and Cloudflare Email Routing’s inbound mail is free.

How many email aliases can you have?

It depends on the provider. As of September 2026, CatchNone allows up to 10 aliases on your own domain on the Free plan and unlimited aliases on your own domains on Lite and Premium. iCloud Mail allows three @icloud.com aliases, Google Workspace 30 per user, and Gmail as many plus addresses as you like. Hide My Email allows “as many addresses as you need.” Free plans include 10 aliases at SimpleLogin and Proton Pass and up to 50 at Firefox Relay (some Relay pages still say 5); addy.io’s allows unlimited aliases under your username but only 10 active ones on its shared domains.

Can an email alias be on a different domain?

Often, yes. Plus addresses stay on your provider’s domain, and iCloud Mail’s own aliases are always @icloud.com. With a domain you own, iCloud+ Custom Email Domain (up to five domains, as of September 2026) or a catch-all brings addresses on that domain to your inbox. CatchNone uses @catchnone.com with Premium, or a domain you own on any plan. Forwarding services use their own domains, or yours on paid plans. One trap: adding a Gmail or Yahoo address to a Microsoft account makes it a sign-in name, and its mail still goes to Gmail or Yahoo.

Why is my email alias not working?

The alias may be switched off or deleted, a lapsed plan may have deactivated it, or the site may reject alias domains or the + sign. A new Google Workspace alias can take up to 24 hours to start working. For a forwarding alias, check the spam folder of the mailbox it forwards to, and check that the forward-to address (Hide My Email’s Forward To setting) is still one you read; why Hide My Email isn’t forwarding walks through the checks. With DuckDuckGo, replies aren’t supported if your forwarding address is on a domain without an SPF record.

Is an alias the same as a throwaway inbox?

No. Temporary inboxes often expire or are public: Mailinator describes its addresses as public inboxes anyone can check. An alias is a private address that lasts as long as you, and the service behind it, keep it running. The difference is covered in the guide to burner email.

Are email aliases secure?

An alias keeps your main address out of a company’s database, which limits what a breach or a sold list exposes. It doesn’t stop phishing, and the alias service handles every message: Apple, for one, says it doesn’t read Hide My Email messages beyond standard spam filtering and deletes them from its relay servers after delivery, usually within seconds. An alias can even give phishing away: a message claiming to be from your bank that arrives at the address you gave a shop is a warning sign, because your bank never had that address.