Outlook and Hotmail Email Alias: How It Works
A Microsoft account alias is a second address that delivers to the same inbox. It is handy for sign-ups, but it has limits that surprise people.
By Siddharth ShankarUpdated October 19, 2026An Outlook.com or Hotmail alias is an extra address attached to your existing Microsoft account. Mail arrives in the same inbox and you can send from the alias in Outlook apps. A Microsoft account can hold up to 10 addresses, with one new alias every two weeks and no more than 10 per year. Removed aliases are retired for good. You can switch off sign-in for an alias so an exposed address cannot be used to log in.
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If you use Outlook.com, Hotmail or Live, you can add alternative email addresses to your Microsoft account. Used well, an alias keeps your main address out of marketing lists. Used carelessly, it can add one more way into your account.
What an alias is
A Microsoft account alias is an alternate address for the same mailbox, not a separate account. As Slipstick explains, mail sent to an alias lands in your existing inbox, and replies come from the address that received the original message. Microsoft’s own wording in the account settings can make this look like a linked account, but it is an alias.
The limits to know before you start
- An account can hold up to 10 addresses.
- You can create one new alias every two weeks, and no more than 10 per year.
- If you delete an alias, a replacement may have to wait until your oldest alias is a year old.
- A removed alias is retired permanently and cannot be reused by anyone, including you.
- An alias cannot be moved to another account or merged later.
Microsoft can change these rules, so treat the numbers as a guide and check the current limits in your account settings.
How to add an alias
1Open your Microsoft account
Sign in at account.microsoft.com and go to the settings for how you sign in to Microsoft.
2Choose Add email
On the account names page, select Add email.
3Create a new address
Choose the option to create a new email address and add it as a username. Pick the name you want and confirm.
4Check your inbox
Send a test message to the alias to confirm it arrives in your normal inbox.
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Sending from your alias
In Outlook apps you can choose the alias in the From field. All aliases share the same display name. Many other mail apps send only from your primary address, so replies from those apps may show the main address instead. That is worth knowing if the goal is to keep your main address private.
The sign-in risk
By default, an alias can also be used to sign in to your Microsoft account. That means an address you give to a shop is also a username for your account. Slipstick suggests turning off sign-in for aliases that you only use for website sign-ups, so a leaked address cannot be used to log in. Combined with a strong, unique password and two-step verification, this removes an easy target.
A tip for tidy sign-ups
Give each alias one purpose, such as shopping or newsletters, and keep a note of which is which. If one starts to attract spam, you can stop using it and keep the rest.
What an alias does not do
An alias hides nothing from Microsoft, and websites can still send mail that ends up linked to your account. It also does not clean up exposure that already exists. If your old address is listed online, see how to remove your email address from the internet. For the wider picture of relay and forwarding options, read our email aliases guide.
Sources
- Slipstick: Microsoft account aliases vs separate accounts (alias shares inbox, 10 addresses, creation limits, sign-in can be disabled)
Frequently asked questions
Is an Outlook alias a separate email account?
No. It is another address for the same mailbox. Mail to the alias arrives in your existing inbox.
How many aliases can I have?
Reports of Microsoft’s rules say up to 10 addresses on an account, one new alias every two weeks and no more than 10 per year. Check your account settings for the current limits.
Can I use an alias to sign in?
It can be set up that way. For aliases used only for sign-ups, switching off sign-in is safer.
Can I delete an alias and reuse it later?
No. A removed alias is retired permanently and cannot be reused by anyone.
Does an Outlook alias make me anonymous?
No. It keeps your main address out of the sign-up form, but the alias is still linked to your Microsoft account.
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