Outlook 365 Not Working Today? Check Status and Fixes

Outlook 365 may be affected by a Microsoft service incident, but I can’t verify live outage conditions from here. Check Microsoft’s service status page or your organization’s Microsoft 365 admin center; if neither reports an incident, use the checks below to determine whether the problem is your account, device, network, or Outlook app.

Is Outlook 365 down today?

There is no reliable way to answer that for every Outlook user without checking current service information. Outlook can mean Outlook on the web, the Windows desktop app, Outlook for Mac, or the mobile app. An issue in one place does not always mean the entire service is down: a desktop app might fail to connect while Outlook on the web still works, or a specific organization’s Exchange Online environment might have a problem while other accounts work normally.

Outlook for Microsoft 365 relies on online services, including Exchange Online for many work and school accounts. Sign-in services, network routing, DNS, and the local app can also affect access. A service incident might cause delays, failed sign-ins, missing or late messages, or problems sending mail. A problem limited to one computer or one account is more likely to need local troubleshooting, though it does not rule out a smaller service issue.

So treat “Outlook is down” as a possibility to verify, not a diagnosis. If you need to send something urgently, first see whether you can use Outlook on the web or another device, and avoid repeatedly changing account settings while the cause is unclear.

How to check Microsoft 365 service status

For a work or school account, the most relevant source is usually the Microsoft 365 admin center. An administrator can sign in and open Health > Service health to check Exchange Online and other Microsoft 365 services. The dashboard reports incidents and advisories relevant to the organization’s services. If you do not have admin permissions, ask your organization’s IT team to check; they can see tenant-specific information that a public status page may not show.

For a broader public check, visit Microsoft’s service status page at status.cloud.microsoft. Look for an incident affecting Outlook or Exchange Online and read the stated impact and latest update. The public page can help identify a widespread issue, but it may not explain a problem confined to one company, school, region, or account. A status page that shows normal service does not prove that your own setup is working.

Third-party outage trackers can offer useful reports from other users, but their charts are based on user submissions, not Microsoft’s internal service data. A sudden spike can be a clue, not confirmation. Search results and social posts can also be outdated or refer to a different Outlook product. Check the timestamp, affected service, and update details before drawing a conclusion.

Work out whether the problem is widespread or local

Compare Outlook in more than one place. If you can sign in to Outlook on the web at outlook.office.com but the desktop app will not connect, the account and core mailbox service may be reachable while the desktop app has a configuration, update, or network problem. If the web app and multiple devices fail for the same account, an account or service-side issue becomes more plausible. If several people at the same organization report the same symptoms, contact IT rather than treating each device as an unrelated failure.

Notice exactly what fails. A blank screen, an error during sign-in, messages stuck in the Outbox, and a slow search are different symptoms. For example, if new messages arrive in Outlook on the web but not in classic Outlook for Windows, focus first on the desktop app’s connection and synchronization. If messages are missing from every client, check the mailbox, account, and service status before rebuilding a local profile.

Also check whether the issue affects only one network. A work device might connect on a phone hotspot but fail on office Wi-Fi because of a network restriction, proxy, VPN, or DNS problem. Do not bypass your organization’s security controls; report the difference to IT, especially on a managed device.

Try these safe checks first

Start with steps that do not remove data or change account security. After each check, retry the action that failed so you can tell whether anything changed.

Check Microsoft’s service status and, for a work or school account, ask IT to review the tenant’s service health.
Confirm you are online by opening another trusted website. If other sites also fail, troubleshoot the network before Outlook.
Try Outlook on the web or a second device. Record whether the same account works there.
Close and reopen Outlook. If it is updating or syncing, allow it to finish before repeatedly restarting it.
Check that you are using the right account and password. Complete any requested multifactor authentication prompt through the normal sign-in flow.
Restart the device if the app remains stuck, then check whether the problem persists.
Install available Office or operating-system updates through your organization’s approved process, especially if the issue began after an update or has lasted several days.

Be cautious with advice to delete mailbox data files, remove an account, disable security software, or reinstall Office as a first step. Those actions can create extra work, disrupt access, or violate workplace policy. A service incident will not be fixed by repeatedly changing a local profile.

Common problems and what they usually indicate

Outlook will not open: The cause might be an app crash, a pending update, an add-in, or a damaged local configuration. If you use classic Outlook for Windows, you can try opening it in safe mode: press Windows key + R, enter outlook.exe /safe, and press Enter. If it opens in safe mode, an add-in may be involved. This is a diagnostic test, not proof that an add-in is the cause; ask IT before disabling workplace-managed add-ins. This command applies to classic Outlook for Windows, not Outlook on the web or the new Outlook app.

Mail will not send: Check the Outbox, connection state, recipient address, attachment size, and any delivery error. A message with a large attachment may be rejected or remain unsent, and an offline app cannot deliver it until it reconnects. For classic Outlook for Windows, check the Send/Receive tab for the Work Offline setting; if it is selected unintentionally, turn it off. The new Outlook and Outlook for Mac have different interfaces, so do not assume that classic Outlook ribbon instructions apply to them.

Mail is missing or late: Search all folders, including Archive, Junk Email, and Deleted Items, and check whether a rule moved the message. Compare the mailbox in Outlook on the web. If the message is absent there too, the issue may involve delivery, the sender, a mailbox rule, or service health rather than the desktop display alone. Ask the sender to confirm the address and whether they received a delivery failure.

Sign-in keeps failing: Check the exact account address, internet connection, and any organization sign-in prompt. A changed password, expired credentials, multifactor authentication, or an administrator’s access policy can interrupt access. Do not approve a sign-in request you did not initiate, and do not share a one-time code with someone claiming to be support.

Search or syncing is slow: A large mailbox, a temporary connection issue, or a local indexing or synchronization delay can make results incomplete. Compare with Outlook on the web and allow time for synchronization. If only one device is affected, tell support which folders or date ranges appear incomplete rather than immediately deleting the local cache.

Differences between Outlook on Windows, Mac, and the web

Microsoft 365 includes several Outlook experiences, and instructions are not interchangeable. Classic Outlook for Windows has a traditional ribbon and account controls; the new Outlook for Windows has a newer interface and may not offer the same settings in the same places. Outlook for Mac uses Mac menus and controls, while Outlook on the web runs in a browser. If a guide says to use a particular ribbon tab or Windows Run command, check that it specifically applies to your version.

On Windows, Office repair is an option when the desktop app repeatedly fails and there is no known service incident. In Windows, open Settings > Apps > Installed apps, select Microsoft 365, choose Modify, and follow the available repair options. The exact labels can vary by Windows and Microsoft 365 installation. Use an organization’s support instructions on a managed computer. On Mac, use Microsoft AutoUpdate to check for Office updates; Windows repair instructions do not apply. On the web, try a supported, updated browser and a private browsing window as a way to check whether a browser extension or saved session is involved.

If you can access mail through the web but not through an installed app, that distinction is valuable when contacting support. State which Outlook version you use, the device and operating system, the time the issue began, and whether web access works. Avoid sending passwords, authentication codes, or private message contents in a support request.

Workarounds and when to contact support

If you have a legitimate need to read or send mail during an app problem, use Outlook on the web or the official Outlook mobile app, provided your organization allows it and you can sign in securely. Confirm that a message actually appears in Sent Items or that the recipient receives it before assuming it was delivered. If you use a shared mailbox, delegated account, or organizational device, some functions may depend on permissions or policies, so a workaround may not behave exactly like the desktop app.

Contact your organization’s IT team when multiple colleagues are affected, a work account cannot sign in, messages appear to be missing, or a security prompt looks unfamiliar. For a personal Microsoft account, use Microsoft’s official support channels and provide the error text, approximate time, app version, and troubleshooting steps already attempted. A screenshot can help, but remove message contents and personal details that support does not need.

If Microsoft reports an active incident, avoid making major local changes while the service team investigates. Follow the incident updates and retry periodically rather than repeatedly changing passwords or rebuilding the Outlook profile. If there is no reported incident and only one installation remains affected, support can help with app repair, account configuration, or a profile issue based on the symptoms.

Frequently Asked Questions

How can I tell if Outlook 365 is down right now?
Check status.cloud.microsoft for a public incident and, for a work or school account, ask an administrator to open Health > Service health in the Microsoft 365 admin center. Compare Outlook on the web with the app. These checks help distinguish a broad incident from a local problem.

Why does Outlook work on the web but not on my computer?
The desktop app may have a connection, update, add-in, or local synchronization issue even when the mailbox is reachable online. Note which app you use and whether it is classic or new Outlook, then try restarting and checking for approved updates. Avoid deleting data files before getting support.

Why is Outlook not sending my emails?
Check whether the message is stuck in the Outbox, whether Outlook is offline, and whether an error mentions the recipient or attachment. For classic Outlook on Windows, inspect Work Offline on the Send/Receive tab. If web mail also cannot send, check service status and ask IT or support for help.

Will restarting Outlook delete my emails?
Closing and reopening Outlook normally does not delete messages stored in your mailbox. However, unsent drafts or locally stored content can be at risk if you remove accounts, profiles, or data files without understanding the setup. Use ordinary restarts first and consult support before destructive changes.

Should I reinstall Outlook if it is not working?
Usually not as the first step. Confirm whether Microsoft reports an incident, compare with Outlook on the web, and try low-risk checks. Reinstallation may not help with a server, account, or network problem, and workplace devices may require IT approval before software changes.

Try it: the Formula Explainer: paste any formula and see each function and reference in plain English.

More in Errors & fixes

Sources: Function behaviour and menu paths: Microsoft Support documentation for Excel. Method & sources

Spotted an error in this guide? Let us know.