Email alias
Also known as: email aliases, alias email address
An email alias is an additional email address that delivers messages to an existing inbox.
Businesses use aliases such as info@ or sales@ that route to staff, while individuals use them to sign up for newsletters or shopping sites without revealing their main address. Services such as Apple's Hide My Email, Firefox Relay, and SimpleLogin create random aliases you can turn off if they start receiving spam. While aliases help privacy and organization, replies sent from the wrong address can still expose your real one.
Email alias, explained at three levels
At home
An email alias is like a P.O. box that forwards everything to your home. People can write to the box without learning your real address. An alias is an extra email address that delivers into your existing inbox, and you can create a different one for each shop or newsletter, then shut one off if it starts attracting spam.
At work
An email alias is an additional address that delivers to an existing mailbox instead of having its own. Businesses use aliases such as info@ or billing@ so customers have a stable address that does not depend on one employee, and so messages reach the right people. Aliases cost nothing extra in Microsoft 365 or Google Workspace, but they need documenting so mail does not go astray.
At home
An email alias is an extra address that delivers to the same inbox. The mail server keeps a list saying that, for example, sales@ and info@ both lead to one mailbox. When a message arrives for an alias, the server looks it up and drops it into the real mailbox, usually showing the original address so you can tell which one was used. Some services also let you send replies from the alias.
At work
Microsoft 365 lets admins add aliases to user mailboxes, and Google Workspace offers similar alternate addresses, with no extra licence. For team addresses, shared mailboxes and Microsoft 365 groups are usually better, since several people can see and respond with clear permissions and history. Plus addressing, such as name+invoices@domain, is supported by Gmail and Exchange Online, letting users create addresses on the fly without admin changes.
At home
Plus addresses are easy, but they reveal your real address, since anyone can just remove the part after the plus. Some sites also reject them. Relay services such as Apple's Hide My Email and Firefox Relay instead generate random addresses that forward to your inbox, and you can turn each one off separately if it starts receiving spam. In my view, a random relay alias is more private anyway, especially for shopping sites and newsletters.
At work
Document every alias, who receives it and why, since undocumented aliases often keep delivering to departed staff's mailboxes, a data leakage and phishing risk. Avoid hanging aliases on individual mailboxes for roles; use shared mailboxes instead. Include aliases in SPF, DKIM and DMARC planning when sending from them, and review automatic forwarding to external addresses, which attackers abuse after compromising accounts.
Real-world examples
At home
Aisha used Hide My Email to sign up for a store's newsletter. When the store suffered a breach, she simply deleted the alias.
At work
Carlos's Montreal MSP replaced a client's habit of using the owner's personal email on its website with a sales@ alias routed to the team's shared mailbox.
How it compares
| feature | Email alias | Separate email account |
|---|---|---|
| Separate inbox | No, shares one | Yes |
| Extra password | No | Yes |
| Can be disabled easily | Yes | Harder |
| Best for | Sign-ups, team addresses | Fully separate identities |
Aliases add addresses without adding inboxes.
For analysts
In small business email setups, I'd map every public-facing address to a shared mailbox or group, not one person's inbox. It survives staff changes.
History & origin
Email systems have long supported aliases and forwarding addresses, going back to Unix mail systems in the 1980s. 'Plus addressing,' such as name+shopping@example.com, was supported by Gmail from its 2004 launch and became popular for filtering and tracking who shared an address. Microsoft added plus addressing to Exchange Online in the early 2020s. Privacy-focused relay services grew as data breaches multiplied: Firefox Relay launched in 2020, Apple introduced Hide My Email with iCloud+ in 2021, and Proton acquired SimpleLogin in 2022. In my view, using aliases is one of the easiest ways to take back control of your inbox.