“Email alias” is used for several mechanisms that behave very differently. A Gmail +shopping address, an Outlook alias, a Google Workspace alternate address, Apple’s Hide My Email and Firefox Relay can all route mail without giving you a second inbox, but they do not provide the same privacy, login behavior, sending options or ability to revoke an address.
Quick answer
Use plus-addressing when you want simple filtering and do not need to hide your base address. Use a provider-level alias when you want another real address attached to the same account. Use a masked or relay address when the point is to avoid giving a site your real address and to retain the option to disable that forwarding address later. Treat "Send as" as a separate capability: it controls the From address on outgoing mail and does not by itself create a receiving alias.
Contents
- Four different things get called an email alias
- Gmail plus-addressing is a variation of the same Gmail address
- A true account alias is another address attached to the same account
- "Send as" is an outgoing identity, not the same thing as an alias
- Masked and relay addresses are designed to hide the destination address
- Which type should you use?
- A practical decision table
Four different things get called an email alias
The easiest way to avoid confusion is to ask what changes in the mail path.
| Mechanism | Example | Where incoming mail lands | Can it hide the real address? | Can it usually be revoked separately? |
|---|---|---|---|---|
| Plus-addressing | name+shopping@gmail.com | Same Gmail inbox | No — base address is visible | No separate address object to revoke |
| Provider-level alias | Alternate Outlook.com or Workspace address | Same account/inbox | Sometimes, depending on use | Yes, subject to provider rules |
| "Send as" identity | Another From address configured in Gmail | Does not define incoming routing | Not necessarily | Remove the sending identity |
| Mask/relay | Hide My Email or Firefox Relay address | Forwarded to real inbox | Yes | Usually yes |
The differences matter for account recovery, spam control and whether a website can infer the address behind the alias.
Gmail plus-addressing is a variation of the same Gmail address
Google calls addresses such as janedoe+school@gmail.com Gmail aliases. Its Gmail Help documentation says mail sent to those variations is delivered to the base janedoe@gmail.com inbox and suggests using them to create filters.
There is nothing separate to provision. The text after the plus sign is simply part of the address variation Gmail accepts.
That makes plus-addressing useful for:
- filtering newsletters, shopping and sign-ups;
- seeing which variation you gave to a service;
- creating easy rules without another mailbox.
It is weak as a privacy mask because the base address remains obvious: remove +shopping and the underlying Gmail address is sitting in plain sight. Some signup forms also reject plus signs or normalize addresses.
A true account alias is another address attached to the same account
Google Workspace and Outlook.com provide a more literal form of alias.
A Google Workspace administrator can add an alternate email address to one user’s primary account. Google says messages sent to that alias automatically route to the user’s primary inbox. The alias is not a separate Google Account, and the user signs in to the primary account to read that mail. Workspace currently allows up to 30 aliases per user at no extra cost.
Outlook.com goes further in one important respect. Microsoft’s alias documentation says aliases share the same inbox, contacts, settings and password, and any alias can be used to sign in to the Microsoft account. You can also choose which alias to send mail from.
That login behavior is a good example of why “alias” is not a portable security concept. An alias that is merely a receiving route at one provider may also be a sign-in identifier at another.
There is another Microsoft-specific caveat: removing an alias that uses a Microsoft-owned domain such as @outlook.com permanently deletes that alias; Microsoft says it cannot later be associated with another Microsoft account.
"Send as" is an outgoing identity, not the same thing as an alias
Gmail lets you configure other addresses in the Send mail as section so a message can carry a different From address. That does not tell you where mail sent to that address is hosted or forwarded. The receiving side is a separate question.
This distinction is becoming more important because Google has announced a current change. Gmail Help says that starting in January 2027, Gmail will no longer support “Send as” for third-party addresses such as Yahoo or Outlook addresses. Google says this does not affect Google Workspace aliases or other Gmail addresses you own.
So an article or tutorial that treats “Gmail alias” and “Gmail Send as” as the same feature will become increasingly misleading.
Masked and relay addresses are designed to hide the destination address
A masked address adds an intermediary.
With Apple Hide My Email, iCloud+ can generate unique random email addresses for websites and apps. Mail is routed through the generated address, and Apple lets users manage those addresses across supported devices and iCloud.com.
Firefox Relay describes the same privacy model more explicitly: the service creates a mask, forwards messages to the real address and keeps that real address hidden from the company receiving the mask. Mozilla says masks can be disabled or deleted later. Its current April 2026 help page says free Relay users can create up to 50 masks.
This changes the risk model. If a retailer leaks random-mask@…, that address can be disabled without changing the real mailbox. A plus-address does not give you that clean separation.
Masking your email address does not remove other recognition signals, such as browser fingerprinting.
WebKit’s October 19 announcement describes another use of email addresses: third-party identity-resolution services can turn them into tracking IDs across sites. Apple says its iOS, iPadOS, macOS and visionOS 27 releases block network access to that infrastructure; unique randomized addresses provide an additional layer against email-based matching.
Relay services can also have limitations. Mozilla advises against masks for some high-importance uses where identity verification, attachments or reliable transactional mail are critical. A bank, doctor or travel document is a poor place to discover that a relay provider has a restriction you did not account for.
If you want your password manager to help create and manage masked addresses, our Proton Pass vs Bitwarden comparison explains their different alias options.
Which type should you use?
For sorting newsletters and sign-ups
Use plus-addressing if the site accepts it. It is almost frictionless, and a Gmail filter can match the exact variation you used.
Do not expect it to hide your main address.
For a professional alternate address
Use a provider-level alias if your mail provider or organization supports it. billing@domain.com can route to the same person as name@domain.com without creating another mailbox.
Check whether the alias can send, receive and sign in independently. Those capabilities vary.
For disposable or privacy-sensitive sign-ups
Use a masked or relay address. This is the category designed to keep the real destination address out of the site’s database and give you a kill switch later.
Keep especially important accounts on an address path you know you can recover long-term.
If the account also uses a passkey, check how passkeys and account recovery work before disabling an address you might need to get back in.
For sending from another address
Configure a legitimate sending identity only when you control the address and understand how it authenticates. Do not assume that receiving an address automatically means your mail client will send from it correctly.
A practical decision table
| What you want | Best fit | Main reason | Watch for |
|---|---|---|---|
| Sort incoming mail | Plus-address | Easy filtering with no setup | Base address remains visible |
| Another branded address in the same mailbox | Provider alias | Separate address, shared mailbox | Provider-specific send/login rules |
| Different From address | Send-as identity | Controls outgoing presentation | Receiving route is separate; Gmail third-party support changes Jan 2027 |
| Hide your real address from a service | Mask/relay | Intermediary forwards without exposing destination | Provider limits and long-term recovery |
| Address you can disable after a breach or spam | Mask/relay or removable provider alias | Revocation without replacing main mailbox | Some provider aliases have irreversible deletion rules |
The word “alias” is too broad to make a decision by itself. Ask four concrete questions instead: Where does incoming mail go? What address appears when I reply? Can the service see my underlying address? What happens if I disable or delete this address?
Sources and verification
- Gmail Help — Send emails from a different address or alias
- Google Workspace Admin Help — Add or delete an alternate email address
- Microsoft Support — Add or remove an email alias in Outlook.com
- Apple Support — Set up and use Hide My Email in iCloud+
- Mozilla Support — Activate Firefox Relay / mask your email address
- Mozilla Support — Create an email mask through Firefox Relay
- WebKit — Blocking Identity Resolution Infrastructure (October 19, 2026)