Fixes / Outlook · Checked September 30, 2026

Outlook cannot connect to the server: meaning and fixes

Short answer

"Outlook cannot connect to the server" means Outlook on your computer can't reach or sign in to your mail server, so mail stops sending and arriving. The usual culprits are Work Offline being switched on or an expired saved sign-in. Check Send / Receive > Work Offline first, then remove saved Office credentials and sign in again.

What this message means

Outlook keeps a copy of your mailbox on your computer and syncs it with a mail server: Microsoft 365/Exchange, Outlook.com, Gmail, or your internet provider's IMAP/POP server. This message means that sync has failed. Either Outlook can't reach the server at all (no network, Work Offline, a VPN or firewall blocking it), or it reaches the server and gets turned away (expired password or token, wrong server settings, an old sign-in method the provider no longer accepts). Your existing mail is still on your computer and on the server. Nothing is deleted. New messages just stay in the Outbox and new mail doesn't arrive until the connection works again.

Common causes

Cause	How to tell
Outlook is set to Work Offline, or the computer has no working internet connection	The status bar at the bottom says "Working Offline" or "Disconnected", and the Work Offline button on the Send / Receive tab looks pressed (shaded). Websites may also fail to load in your browser.
A saved sign-in (password or token) has expired or is corrupted	Webmail (outlook.office.com, outlook.live.com or gmail.com) works fine in a browser with the same account, but the Outlook app says "Disconnected", "Trying to connect..." or "Need password", or keeps asking for your password.
Wrong server settings, or a sign-in method the provider has switched off (common with Gmail and other IMAP/POP accounts)	Only one account fails, often right after you changed your password or turned on 2-Step Verification, or after an update. Errors mention the incoming (IMAP/POP) or outgoing (SMTP) server, or say the server doesn't support the encryption type you specified.
An add-in, VPN, proxy or antivirus email scanning is interfering with the connection	Outlook connects when you start it with outlook.exe /safe, or when you disconnect the VPN or pause antivirus, and fails again in normal mode.
A damaged Outlook profile or local data file	The problem continues after you've re-entered the password and the account works everywhere else (webmail, phone, another PC). Sometimes it shows up after a Windows or Office update.
A service outage or a change on the mail server itself	Webmail fails too, or several people in your organisation hit the same error at the same time.

How to fix it

1. Turn off Work Offline and confirm the connection

Look at the status bar at the bottom of Outlook. If it says "Working Offline" or "Disconnected", continue with the next step.
Classic Outlook for Windows: open the Send / Receive tab and click Work Offline once so it's no longer shaded. Outlook for Mac: open the Outlook menu in the top menu bar and make sure Work Offline is unticked.
Open any website in your browser to confirm you're online. If you're on a VPN, disconnect it and test again.
Sign in to your webmail in a browser (outlook.office.com for work or school, outlook.live.com for Outlook.com, mail.google.com for Gmail). If webmail also fails, the problem is the account or the service, not your computer.
Close Outlook completely, wait 10 seconds, reopen it and give it 30 seconds to reconnect.

2. Remove saved Office credentials and sign in again

Classic Outlook for Windows (Windows 10 and 11). On a Mac, remove the account under Outlook > Settings > Accounts and add it again.

Close Outlook.
Press the Windows key, type Credential Manager and open it.
Click Windows Credentials.
Find entries that belong to Office or Outlook, such as ones named MicrosoftOffice16_Data... or starting with MS.Outlook, plus any that show your email address.
Click the arrow next to each one, click Remove, and confirm.
Reopen Outlook and sign in when prompted. If the sign-in window asks for multi-factor approval, complete it.

3. Fix the sign-in method and server settings for Gmail and other IMAP/POP accounts

Classic Outlook for Windows with Gmail, iCloud, internet provider or hosting-company email. Microsoft 365 and Outlook.com accounts don't use these settings.

Gmail no longer accepts your normal Google password from apps. The simplest fix is to remove the account (File > Account Settings > Account Settings, select it, click Remove) and add it again with File > Add Account, then choose Sign in with Google in the browser window.
If you have to enter a password manually and your provider requires 2-Step Verification, create an app password in the provider's security settings and use that instead of your normal password.
To check the settings, go to File > Account Settings > Server Settings (or Account Settings > Account Settings > Change > More Settings > Advanced tab in older builds).
Compare the server names, ports and encryption with your provider's published values. For Gmail: incoming imap.gmail.com, port 993, SSL/TLS. Outgoing smtp.gmail.com, port 587 with STARTTLS or port 465 with SSL/TLS.
If the error says the server doesn't support the encryption type, set encryption to match the port exactly (993/465 = SSL/TLS, 587 = STARTTLS) rather than Auto, and click Next or Done to test.

4. Rule out add-ins, VPN, proxy and antivirus

Classic Outlook for Windows

Close Outlook, press Windows + R, type outlook.exe /safe and press Enter.
If Outlook connects in safe mode, an add-in is the likely cause. Restart Outlook normally, go to File > Options > Add-ins, set Manage to COM Add-ins and click Go.
Untick all add-ins, restart Outlook, then turn them back on one at a time to find the one causing the problem.
If safe mode doesn't help, temporarily disconnect any VPN and pause email scanning in third-party antivirus, then test again.
On a work device, ask IT whether a proxy or firewall change is blocking Outlook's connection to the mail server.

5. Repair the account or create a new Outlook profile

Classic Outlook for Windows. The new Outlook for Windows doesn't use profiles: remove and re-add the account under Settings > Accounts instead.

Go to File > Account Settings > Account Settings, select the account on the Email tab and click Repair, then follow the wizard and restart Outlook. (Repair is greyed out for some Microsoft 365 accounts. If so, go to the next step.)
To create a new profile, close Outlook and open Control Panel. Set View by to Small icons and open Mail (Microsoft Outlook).
Click Show Profiles, then Add, type a name (for example New) and click OK.
Sign in with your email address in the wizard that opens.
Back in the Mail window, select Always use this profile, pick the new profile, click OK, and open Outlook. It will download your mail again. The old profile stays until you remove it.

6. Update and repair Office

Windows 11 uses Settings > Apps > Installed apps. Windows 10 uses Settings > Apps > Apps & features.

In Outlook go to File > Office Account > Update Options > Update Now, and let the update finish.
Run Windows Update (Settings > Windows Update > Check for updates) and restart.
If the error continues, open Settings > Apps > Installed apps (Windows 11) or Apps & features (Windows 10), find Microsoft 365 or Microsoft Office, and choose Modify.
Pick Quick Repair first. If that doesn't help, run Online Repair (it needs an internet connection and takes longer).

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Still not fixed?

If webmail works but Outlook still won't connect after a new profile, the account is fine and the problem is on your computer. Test the same account on another computer or on your phone to confirm. For a work or school Microsoft 365 account, contact your IT admin. They can check Exchange Online service health in the Microsoft 365 admin center and run Microsoft's Outlook connectivity diagnostics, which need an admin account. For Gmail, iCloud or internet provider email, check the provider's status page and its official Outlook setup instructions. If webmail also fails, the provider has to fix it on their side.

Questions people ask

Why does Outlook say it cannot connect to the server when my internet is working?

Usually Outlook is reaching the server but being refused because the sign-in it saved has expired or is corrupted. Clearing the Office entries in Windows Credential Manager and signing in again fixes most of these cases.

Will I lose my emails if I create a new Outlook profile?

Not for Microsoft 365, Outlook.com, Exchange or IMAP accounts, because the mail is stored on the server and downloads again into the new profile. With a POP account, mail may exist only in your local .pst file, so note its location and reopen it in the new profile with File > Open & Export > Open Outlook Data File.

Why did Gmail stop working in Outlook after years of working fine?

Google no longer accepts plain username-and-password sign-in from third-party apps. Remove the Gmail account from Outlook and add it again using Sign in with Google, or use an app password if you have 2-Step Verification turned on.

How do I get Outlook out of Working Offline mode?

In classic Outlook for Windows, open the Send / Receive tab and click Work Offline once so it's no longer highlighted. On a Mac, untick Work Offline in the Outlook menu.

Is Outlook down right now?

Sign in to webmail in a browser. If that fails as well, the service is probably having problems. Microsoft 365 admins can confirm this on the service health page in the admin center, and personal users can check the provider's status page.

Sources

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