Outlook Disconnected in Microsoft 365? 6 Fixes That Work

When Outlook shows Disconnected or Trying to connect in the bottom status bar, new mail stops arriving and anything you send sits in the Outbox. In my experience on the help desk, it almost always comes down to one of four things: a changed password, an expired sign-in token, a damaged Outlook profile, or Outlook stuck in Work Offline mode. Here is the order I check them in.

Quick answer

First check Outlook is not in Work Offline mode (Send / Receive tab). Then restart Outlook and sign in again when asked. If it stays disconnected, remove old entries for MicrosoftOffice16 in Credential Manager, disconnect and reconnect your account under Settings > Accounts > Access work or school, and as a last step create a new Outlook profile from Control Panel > Mail.

Why Outlook says Disconnected

• You changed your password, or it expired, and Outlook is still using the old one.
• The PC was off or offline for weeks and the sign-in token expired.
• The Outlook profile or the offline mailbox file (.ost) is damaged.
• Work Offline was switched on by accident.
• The internet, a VPN or a proxy is blocking Outlook, or Microsoft 365 itself has an outage.

Fix 1: Turn off Work Offline

Open the Send / Receive tab. If Work Offline is highlighted, click it once to turn it off. Click it twice if it was not highlighted; toggling it often forces Outlook to reconnect.

Fix 2: Check the basics

• Open Outlook on the web. If you cannot sign in there either, the problem is your account or password, not Outlook.
• Check the Microsoft 365 service status. Admins can see it in the Microsoft 365 admin center under Health > Service health.
• Disconnect any VPN and try again.

Fix 3: Clear saved Office credentials

1. Close Outlook, Teams and other Office apps.
2. Open Control Panel > Credential Manager > Windows Credentials.
3. Remove every entry that starts with MicrosoftOffice16_Data or mentions your work email.
4. Open Outlook and sign in again.

Fix 4: Reconnect your work or school account

1. Open Settings > Accounts > Access work or school.
2. Select your work account and click Disconnect. On a company-joined PC, skip this and ask IT, because disconnecting can remove the device from management.
3. Restart, open Outlook and sign in. If you see a TPM error at this point, follow fix the Trusted Platform Module has malfunctioned error.

Fix 5: Create a new Outlook profile

A damaged profile is the most common cause when nothing else works. A new profile downloads your mailbox again from the server, so you do not lose any mail stored in Microsoft 365.

1. Close Outlook and open Control Panel > Mail (Microsoft Outlook). Set Control Panel to Small icons if you cannot see it.
2. Click Show Profiles > Add, type a name and follow the steps with your email address.
3. Select Always use this profile, choose the new one and click OK.
4. Open Outlook and wait for the mailbox to download. Large mailboxes can take a while.

Keep any local PST files you use, such as old archives, and add them to the new profile with File > Open & Export > Open Outlook Data File.

Fix 6: Repair Office

Go to Settings > Apps > Installed apps > Microsoft 365 > Modify, run a Quick Repair, and if that does not help, an Online Repair. The Get Help app also has an Outlook connection troubleshooter that runs most of these checks for you.

Using the new Outlook?

The new Outlook for Windows does not use profiles, Credential Manager entries or .ost files the same way. If it will not connect, remove the account from Settings > Accounts inside new Outlook and add it again, or switch back to classic Outlook with the toggle at the top right.

More Outlook fixes: user accounts in Outlook and Teams do not match and free up mailbox space with online archives.

Frequently asked questions

Why does Outlook keep saying Disconnected?

Usually because of a changed or expired password, an expired sign-in token, Work Offline mode, or a damaged Outlook profile. Check Work Offline first, then sign in again, then create a new profile.

Will creating a new Outlook profile delete my emails?

No, not for Microsoft 365 or Exchange mailboxes. Mail is stored on the server and downloads again into the new profile. Local PST files are not deleted, but you need to add them to the new profile.

How do I clear Outlook saved passwords?

Close Office apps, open Credential Manager, go to Windows Credentials, and remove entries that start with MicrosoftOffice16. Outlook asks you to sign in again the next time it opens.

Is Outlook disconnected because of a Microsoft outage?

Sometimes. Try Outlook on the web; if that also fails, check the Microsoft 365 service status page or ask your admin to check Service health.

Does this work for the new Outlook?

The new Outlook does not use classic profiles. Remove and re-add the account inside new Outlook, or switch back to classic Outlook to use these steps.