Mailbox provider · Outlook.com
How to verify an Outlook.com address
Can you verify an Outlook.com address?
Partly, and not the mailbox right now. A checker can confirm the syntax, the mail servers and disposable or role patterns. Microsoft is currently refusing mailbox checks from our server's network, so SimpleVerifier doesn't probe @outlook.com and returns every well-formed address as risky, never valid. Only a delivery, open or reply proves it.
Tuned for outlook.com, hotmail.com, live.com, msn.com. Five checks a minute, no account needed. Nothing is sent to the address — we ask its mail server whether the mailbox exists, then disconnect.
Paste your @outlook.com addresses (a mixed list is fine) and check them together.
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Outlook.com verification facts
| Primary mail server (MX) | outlook-com.olc.protection.outlook.com (run by Microsoft) |
|---|---|
| Made-up address, 23 October 2026 | risky in both rounds, about 10.5 hours apart ("Provider hides mailbox status") |
| Mailbox probe | Not right now. Microsoft is refusing mailbox checks from our server's network, so the checker skips the probe. |
| Catch-all behaviour | Unknown, because we can't ask right now. Treated the same as unconfirmed. |
| Typical results | Risky ("Provider hides mailbox status") for well-formed addresses, never valid. Invalid only for bad syntax. |
| Always checked | Syntax, the domain's mail servers (MX), disposable domains, role inboxes (info@, sales@) and likely typos. |
| A list of addresses | Paste or drop it above: the first 100 checks are free with a Google sign-in, no card, results as a CSV. |
| Single-address tool | Outlook checker |
From our checker's code and our own dated measurements. Anything we cannot confirm is reported as risky, never valid. Last updated .
How do I check if a @outlook.com address exists? You can check the syntax, mail servers and disposable or role patterns, but not the mailbox right now: Microsoft is refusing mailbox checks from our server's network, so SimpleVerifier doesn't probe @outlook.com and returns it as risky ("Provider hides mailbox status"), never valid. The domain receives mail; only mail history (a clean delivery, an open or a reply) proves a @outlook.com address is live.
Can you verify @outlook.com addresses?
Not right nowNo, not right now. Microsoft is refusing mailbox checks from our server's network, so @outlook.com isn't probed.
Outlook.com does reject unknown users during the SMTP conversation, but Microsoft currently refuses checks from our server's network before the mailbox question, so a probe would only get that refusal. The checker skips it and returns @outlook.com addresses as risky with the reason "Provider hides mailbox status". It always checks the syntax, the domain's MX records, disposable domains and role addresses such as info@ first.
Provider hides mailbox statusWhat we can and cannot confirm at @outlook.com
We can confirm
- The address is written correctly (syntax), and the domain publishes working mail servers (MX).
- Whether it is a disposable or role address (info@, sales@) or a likely typo of a bigger domain.
We cannot confirm
- Whether a single @outlook.com mailbox exists. Microsoft is currently refusing checks from our server's network, so we don't probe Outlook.com mailboxes and every @outlook.com address comes back risky ("Provider hides mailbox status"), never valid.
- Which of those risky addresses will bounce. Use engagement history, or a small first batch.
- Whether a person reads the inbox, wants your email or agreed to receive it. No checker can see that.
Anything we cannot confirm comes back risky, never valid.
What we measured at outlook.com
Measured by SimpleVerifier on 23 October 2026 through our production checker and public DNS. No message was sent and no real person's address was used.
| Made-up address, checked twice ~10.5 hours apart | risky both times ("Provider hides mailbox status") |
|---|---|
| Primary mail server (MX) | outlook-com.olc.protection.outlook.com |
| Mail host | Microsoft |
| DMARC policy | p=none |
| SPF | published, ends -all |
| MTA-STS | published |
| DNSSEC | signed (DS record) |
Sources: How 51 mailbox providers answer verification checks, SPF, DMARC, MTA-STS and DNSSEC at 51 mailbox providers, both with CSVs (CC BY 4.0). All datasets: research.
Where your @outlook.com addresses live
Already paying another verifier?
Outlook.com addresses can't be confirmed by our checker right now. Outlook.com does reject unknown users during the SMTP conversation, but Microsoft is currently refusing mailbox checks from our server's network, so outlook.com addresses come back risky rather than valid or invalid. When Microsoft does reject a recipient, the reply is 550 5.5.0 Requested action not taken: mailbox unavailable, which locked accounts also receive. First make sure the address is consumer Outlook.com and not a company on Microsoft 365, which behaves differently.
Price: this tool is free. Checking a whole email list is from $9/mo, and the first 100 checks are free with Google, no card. See pricing
Live DNS snapshot: outlook.com
Checked 6 November 2026, 10:22 UTCRead from DNS at the time shown and refreshed at most once a day. MX says where mail for outlook.com goes; SPF and DMARC describe mail sent from it, not whether any one address exists.
- 5
outlook-com.olc.protection.outlook.comOutlook.com (Microsoft consumer)
First MX host belongs to Outlook.com (Microsoft consumer).
v=spf1 include:spf2.outlook.com -allp=none: meets the requirement, but blocks nothing.
v=DMARC1; p=none; sp=quarantine; pct=100; rua=mailto:[email protected]; ruf=mailto:[email protected]; fo=1Look up any other domain with the MX lookup or the email provider lookup.
Outlook.com at a glance
| Operated by | Microsoft Corporation, Redmond, WashingtonSource: Microsoft Services Agreement |
|---|---|
| Same mailbox system | outlook.com, hotmail.com, live.com and msn.com each point at their own olc.protection.outlook.com host; regional domains such as hotmail.co.uk and outlook.fr use eur.olc.protection.outlook.comObserved 7 October 2026 (dig MX) |
| MX hosts | outlook-com.olc.protection.outlook.comObserved 7 October 2026 (dig MX) |
| Answer to a made-up address | Not probed: Microsoft is refusing mailbox checks from our server's network, so a made-up address came back risky. Rejections of unknown users read 550 5.5.0 mailbox unavailableObserved 7 October 2026 (SimpleVerifier's live checker on a made-up recipient, no message sent) |
| Address rule | One Microsoft account can carry several addresses (aliases) that all deliver to the same inboxSource: Microsoft: email aliases in Outlook.com |
| Inactive accounts | The mailbox is closed and its email deleted after a year without a sign-in; the Microsoft account itself after two yearsSource: Microsoft support: missing Outlook.com email |
| Bulk sender rules | Over 5,000 messages a day to Outlook.com, Hotmail and Live addresses: SPF, DKIM and DMARC required since 5 May 2025Source: Microsoft Defender for Office 365 blog |
First, check which Microsoft you are dealing with
"Outlook" covers two systems that answer a mailbox check differently. Consumer Outlook.com addresses resolve to hosts ending in olc.protection.outlook.com. A business on Microsoft 365 publishes an MX ending in mail.protection.outlook.com, usually in the form company-com.mail.protection.outlook.com. A company whose MX points somewhere else entirely has a security gateway in front, and you are verifying against the gateway's rules, not Microsoft's. The MX lookup tool shows which case you have.
Microsoft 365 tenants that host every mailbox in the cloud reject unknown recipients with 550 5.4.1 "Recipient address rejected: Access denied", which Microsoft's Directory-Based Edge Blocking documentation describes. Despite the wording, it means the address does not exist, not that you are blocked.
Reading a consumer Outlook.com rejection
Unlike Google, Microsoft does not publish a reference table for its consumer service's SMTP replies, so 550 5.5.0 has to be read from behaviour. It is good evidence that a mailbox is gone, but senders on Microsoft's own Q&A forum have reported the same reply for accounts that were locked pending phone verification. One rejection is a strong hint; two rejections a day or more apart are close to certain.
Watch the class of the code too. RFC 3463 reserves the x.7.x class for security or policy status, so a 5.7.1 from Microsoft is a refusal of the sending or checking server, not a verdict on the address. A verifier that reads every 550 as "invalid" would delete real Outlook users. Returning uncertain Outlook.com results as risky is the honest answer, and it is what our checker does while Microsoft refuses checks from our server's network.
Outlook.com lists go stale in a year
Microsoft's support page says that if you have not signed in to an Outlook.com mailbox at least once in a one-year period, Microsoft will close it and delete all email, and the Microsoft Services Agreement requires a sign-in at least once in two years to keep the account. That is a shorter fuse than Gmail's two years, so a consumer list that has not been mailed or checked for twelve months deserves a fresh check. We could not find a Microsoft statement on whether a closed address can be registered again, so we make no claim either way.
Common questions
- How do I check if a @outlook.com address exists?
- You can check the syntax, mail servers and disposable or role patterns, but not the mailbox right now: Microsoft is refusing mailbox checks from our server's network, so SimpleVerifier doesn't probe @outlook.com and returns it as risky ("Provider hides mailbox status"), never valid. The domain receives mail; only mail history (a clean delivery, an open or a reply) proves a @outlook.com address is live.
- Can I check a list of Outlook.com addresses for free?
- Yes. Paste the list or drop a CSV on this page and sign in with Google: the first 100 addresses are checked free, no card, once per account, and the results download as a CSV. Single addresses can be checked on this page without an account, five a minute.
- Does checking an Outlook.com address send them an email?
- No. For @outlook.com the checker does not even contact the mailbox: it checks the syntax, mail servers and disposable or role patterns only. Nothing is sent and the owner is not notified.
- Why does my Outlook.com address come back risky?
- Because Microsoft is refusing mailbox checks from our server's network right now, so the mailbox wasn't confirmed and the honest result is risky ("Provider hides mailbox status"). The domain receives mail. Risky means unconfirmed, not bad. Send to those addresses in a small first batch, or only where the address came from a sign-up you trust.
- How can I tell if an Outlook.com address is real?
- A mailbox check can, because Outlook.com rejects unknown users, but ours can't run one right now: Microsoft is refusing mailbox checks from our server's network, so outlook.com addresses come back risky rather than valid or invalid. When Microsoft does reject, it replies 550 5.5.0 'mailbox unavailable', which locked accounts can also get, so re-check before removing a large share of a list.
- Is a company using Outlook the same as an outlook.com address?
- No. Companies use Microsoft 365, whose MX records end in mail.protection.outlook.com and which rejects unknown recipients with 550 5.4.1. Consumer Outlook.com uses hosts ending in olc.protection.outlook.com and replies differently.
- How long does an unused Outlook.com address keep working?
- Microsoft says an Outlook.com mailbox is closed and its email deleted if nobody signs in at least once in a one-year period. The Microsoft account itself is closed after two years without a sign-in.
- Do Microsoft's bulk sender rules apply to outlook.com recipients?
- Yes. Since 5 May 2025 Microsoft has required SPF, DKIM and DMARC from domains sending more than 5,000 messages a day to its consumer addresses, including outlook.com, hotmail.com and live.com, and rejects non-compliant mail with 550 5.7.515.
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