Summary:
“Cannot connect to the server” is one of the most common errors you’ll run into with Outlook. It won’t just block you from sending mail, it’ll stop you from receiving it too. This article walks you through a handful of simple manual fixes so you can get past the Outlook “cannot connect to the server” error without much hassle.
To send or receive any emails in Outlook, you need a connection to the Outlook Exchange Server. When that connection fails, your folders can’t sync with the server either. When this happens, Outlook throws up an error that reads “Outlook cannot connect to the server. If you continue to receive this, content the server administrator or ISP“.
Table of contents:
Reasons why Outlook won’t connect to the server
How do I get Outlook to connect to the server?
Why Outlook Cannot Connect to the Server?
If you’re trying to figure out why Outlook keeps dropping its connection to the server while you’re working offline, here are a few reasons it might be happening.
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- OST synchronization errors
- Damaged Outlook data files
- If a mailbox on the Exchange server gets deleted or disabled, you can run into connectivity issues as a result.
- Damaged Microsoft Office or Outlook program files
- A corrupt Outlook profile or an incompatible or faulty add-in can also leave Microsoft Outlook unable to connect to the server.
Whatever’s causing it, you’ll want to fix the error quickly so you can get back into your Outlook mail. Let’s get right into how to fix the error and reconnect Outlook to the server.
How to Fix the Error Outlook Cannot Connect to the Server?
Before you get into the methods below, here are a few basic fixes that can help you troubleshoot Outlook connectivity issues. They can work for other issues too, like the server is not available error.
Outlook cannot connect to server but internet is working
If your browser loads pages fine but Outlook still throws the connection error, the problem is almost never your internet connection. It is usually one of three things: Outlook is stuck in Work Offline mode, your Exchange account needs re-authentication, or a firewall is blocking Outlook specifically while letting your browser through.
Start with Send/Receive > Work Offline in the ribbon. If that button is highlighted, click it to toggle Outlook back online. If that is not it, check whether Modern Authentication has expired on your account. This shows up as repeated password prompts that never seem to stick, usually because a security policy update on the Exchange or Microsoft 365 side invalidated your cached token. Go to File > Account Settings > Account Settings, select the account, and click Repair to force Outlook to re-authenticate.
Antivirus software and third-party firewalls are the other common cause. Programs like Bitdefender or Norton sometimes scan Outlook’s connection to port 443 and quietly drop it. Temporarily disabling email scanning in your antivirus (not the whole antivirus) is the fastest way to confirm this is the cause before you go digging through Windows Defender Firewall rules.
Basic troubleshooting methods to fix Cannot Connect to the Server
Verify your account credentials or Exchange server name
Check the Computer and Network Connection
Disable the Extension or Add-ins
Basic Fix 1: Verify your account credentials or Exchange server name provided are correct
If your account details or Exchange server name are wrong, Outlook won’t be able to connect to the server when you run the software. Follow the steps below to make sure your account credentials in Outlook are correct.
Step 1: Open Outlook on your computer. Go to File > Info > Account settings
Step 2: Click on the account from the dialog box > remove the existing account > re-enter your correct account credentials
If you’re still running into the error, check your internet connectivity next.
Basic Fix 2: Check the Computer and Network Connection
If there’s a problem with your network, or it just isn’t working, you won’t be able to connect to any server. In that case, make sure your internet connection is up and your system is actually connected to that network.
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- First, try connecting another device to the same network. If Outlook opens fine on that device, you can conclude the network itself isn’t the problem.
- Next, try accessing your browser and check if you can pull up your emails there. If you can’t connect, that points to a problem with the server.
- If you’re on a public network, try switching to a private one and see if the connection works.
Basic Fix 3: Check Outlook is Online
There are a few ways to tell whether Outlook is online or offline. Start by checking the Outlook status bar at the bottom, if it says Working Offline or Disconnected, your Outlook isn’t connected to the server. Here’s how to reconnect it:
Open Outlook >> Go to the Send/Receive tab >> Select the Work Offline option to reconnect.
Basic Fix 4: Use SSL to connect to Exchange server
An SSL certificate verifies the authenticity of the Exchange Server and lets you connect to it securely.
Here’s how to use SSL to connect to the Microsoft Exchange server:
Step 1: Open Outlook. Go to File > Info > Account settings
Step 2: Select your email account >> click on Change > More Settings > Advanced tab
Step 3: Now select SSL as the type of encrypted connection and click Ok.
Basic Fix 5: Disable the Extension or Add-ins
If a faulty add-in or a disabled extension is to blame, your best bet is to disable each one and try connecting again.
Step 1: Open Outlook. Go to the File > Options > Add-ins from the left bar
Step 2: Click on the Go button, uncheck all the extensions, and hit the Ok button.
Now, restart Outlook and check whether the problem’s resolved.
Those are a few basic connectivity troubleshooting methods. If you’re still hitting the “Outlook cannot connect to the server” error, the issue is probably something inside Outlook itself. Try the methods below to get Outlook reconnected to the server.
Outlook cannot connect to server error 0x800CCC0E
Error 0x800CCC0E means Outlook could not open a connection to the outgoing (SMTP) or incoming (POP3/IMAP) mail server within the timeout window. It is a POP/IMAP account error more than an Exchange one, so if you are on a work Exchange or Microsoft 365 account, this code usually points to a port or SSL mismatch instead of account damage.
- Open File > Account Settings > Account Settings, select the account, and click Change > More Settings > Advanced.
- Check that the outgoing server port matches your provider (587 with STARTTLS, or 465 with SSL, are the two common combinations; 25 is blocked by most ISPs now).
- Confirm
4 Methods to Connect Outlook to the Server
Here are the methods that’ll help you fix Outlook’s connectivity with the server:
Verify the connection with proxy server
Fix Corrupt Outlook data File (OST, PST)
Method 1: Configure a Connection to a Proxy Server
If you’re using a proxy server for internet access, you’ll need a few extra connection configuration steps to fix the problem.
Step 1: Open Outlook. Click on the File > Info > Account settings
Step 2: Select your account and click on Change> More Settings > Connection tab.
Step 4: Choose the Connect to Microsoft Exchange using the HTTP option.
Step 5: Click on Exchange Proxy Settings to specify a proxy server. Then enter a URL to connect to that proxy server, and select Connect using SSL only.
Step 6: Select Only connect to proxy servers that have this principal name in their certificate, then enter must: URL
Step 7: Under Proxy authentication settings, select the authentication type: Basic authentication or NTLM authentication and hit Ok.
If your Outlook is unable to connect to the proxy server, check that out for more ways to solve it.
Method 2: Repair Outlook Account
Your Outlook account holds the info tied to the servers and email addresses you’ve entered into Outlook. Repairing an Outlook profile could be all it takes to fix the problem.
Step 1: Open Outlook. Click on File > Info > Account settings
Step 2: Now select your account and hit the Repair button
Step 3: You’ll be asked to enter your account details to confirm your account.
Step 4: Hit the Next button. This lets Outlook automatically reconnect with the server and diagnose whatever problem might be there.
This should take care of the problem. If you’re still stuck, move on to the next method.
Method 3: Rebuild Outlook Data file
You can also try rebuilding the entire Outlook data file to resolve the “cannot connect to the server” error.
Step 1: Open Account Settings in Outlook.
Step 2: Click the Data Files tab, choose the Email account, then click Open File Location.
Step 3: Now you can rename the file, or move it somewhere else. Launch Outlook again, and it’ll automatically try to recreate your data file.
Method 4: Fix Corrupt Outlook Data File
If the “cannot connect to the server” problem comes down to damaged or corrupt data files in Outlook, that’s fixable. If the issue is with your OST file, you can convert OST to PST and repair the PST file instead.
To do that, you can run a built-in repair utility like ScanPST, which handles minor corruption just fine. But if the corruption’s more severe, you’ll want a third-party tool to repair your corrupted PST files.
SFWare PST repair is the tool we’d recommend most for fixing Outlook data file corruption. It can restore your entire mailbox data, contacts, emails, tasks, and more. And once your data’s verified, you can save it as PST or another format of your choosing.
Steps to Repair Outlook Data File
Step 1: Download and install the SFWare PST repair tool on your computer and launch it. You’ll see three options on the main screen:
1: Open PST file: Pick this if you already know where the PST file is located
(you’ll be taken to the next screen, where you can browse to the PST file)
2: Find PST file: Pick this if you’re not sure where the PST file is located
3: Select Outlook Profile: Use this to find the PST file tied to a specific profile, if you’ve got multiple Outlook profiles.
Step 2: Once you’ve selected the PST file, click Normal Scan, pick a location to save the repaired PST file, then click the Repair button
Step 3: Once the file’s repaired, you can Preview it along with the recovered emails, then Save the repaired PST wherever you’d like
If none of the above gets you past the “Outlook cannot connect to the server” error, you can try reinstalling Outlook. That should clear up pretty much any Outlook errors left standing.
Conclusion:
That covers the workarounds that should get you past “Outlook cannot connect to the server.” And if the root cause is damage to your Outlook data file, you can lean on the SFWare PST repair tool to fix it.
Frequently Asked Questions
What to do when Outlook Mac cannot sync with the server?
To fix Mac Outlook not connecting to the Exchange server, check whether Outlook’s stuck in offline mode, and try rebuilding Outlook on your Mac. Check out this guide for more on how to fix Outlook Mac not synchronizing with the Exchange server.
Why does my Outlook not connect to the server?
There are plenty of reasons Outlook might fail to connect to the server. OST files stuck in offline mode, damaged Outlook data files, internet connectivity issues, and more are the usual suspects. Whatever’s behind it, you can fix it using the methods covered in this article.
How do I fix the Outlook connectivity error?
If you’re dealing with connectivity issues between Outlook and the server, the methods above should help. Start with the basics: verify your Outlook account or Exchange server name, check your internet connectivity, and get Outlook out of Work Offline mode. Beyond that, you can add SSL to the server and disable any faulty add-ins.
