Outlook Cannot Connect to Server: 10 Solutions

Outlook errors can be a major pain because they prevent you from accessing or properly using your emails. If you are experiencing a recurring issue where Outlook cannot connect to the server, then this guide can help.

It’s vital that you stay connected to your email because it’s often your lifeline to important work information. Continue reading to learn in-depth information on how email clients work, how Outlook and Microsoft Exchange work together, and how to fix this connection issue. 

How does Microsoft Outlook work?

Microsoft Outlook is an email client, and it is part of the Microsoft Office suite. In short, email clients are applications that allow you to manage your email account. This means Outlook is a piece of software dedicated to handling your emails that it retrieves through various protocols. Email clients can either be web-based, think about Gmail, or can be desktop applications, such as Outlook. Most are both to some degree. 

With Outlook, you can use the interface to navigate the email client and manage your emails. The app even includes calendar and meeting integration.

Multiple protocols exist for the sending and receiving of emails. The most common protocols are POP3, IMAP, SMTP, HTTP, and EAS. Each protocol has slightly different functionalities and security. 

Outlook itself is NOT an email service. To send and receive emails, it needs to connect to an email service, like a Microsoft Exchange server. Microsoft Exchange uses a proprietary protocol called MAPI.

What’s the difference between Exchange and Outlook?

Outlook and Exchange may seem to do the same thing at first, and while they are both Microsoft products, they have very different purposes. You can’t directly compare Exchange vs. Outlook because they are more like complementing products.

Outlook is an email client, whereas Exchange is a mail server. These two pieces combine for an integrated email service that many Microsoft users enjoy. Typically an on-premise setup of Outlook and Exchange offers better security than many webmail options. That’s why many corporations still manage their email in-house instead of opting for a cloud solution like Microsoft 365 or G Suite.

What does it mean when Outlook cannot connect to server?

For Outlook to connect to the Exchange email server – or any other email server – without issues, a few things need to work properly. 

Outlook needs to be connected to the internet, so the software can verify your credentials and reach out to the Exchange email server. If there is something wrong with the internet connection, your credentials, or the Exchange email server itself, Outlook may have issues connecting. 

Check out this quick list of the common reasons Outlook cannot connect to the server:

  • Outlook software is corrupt and needs repair or a clean install
  • Outlook software is outdated and uses outdated protocols or connection information 
  • Outlook cannot verify user credentials
  • Outlook is in Work Offline mode
  • Personal Folder File (.PST) is corrupt 
  • Outlook Extension conflicts
  • Exchange email server is down or experiencing an outage

How to fix the Outlook cannot connect to server issue

In the methods below, we are going to focus on the connection between Outlook and an Exchange email server, but the same troubleshooting principles apply even if you use a different email server.

1. Restart Outlook

If you haven’t tried this yet, it should be your first move whenever troubleshooting an issue with your computer. Restarting the software allows for it to boot cleanly. This can fix any issues that may be keeping Outlook from connecting to the Exchange email server. 

To restart Outlook:

  1. Navigate to your current instance of Outlook. Click File from the top menu. 
  2. Click Exit on the left-hand side. 
Outlook File menu
  1. Reopen Outlook to see if the issue is resolved. Outlook will usually indicate in the bottom-right hand corner if it’s syncing with the Exchange server. Or if Outlook is connected to the Exchange server.
Outlook connected to Microsoft Exchange server.

2. Check your login and password

If you are just setting up your Outlook for the first time on a new computer or workstation, then wrong credentials are commonly the cause of the Outlook cannot connect to server issue. It’s very easy to misspell your username or password when trying to log in. 

If either of these is spelled wrong, Outlook will attempt to connect to the Exchange server before being kicked when no username with that password is found. Once you’ve got your login correctly entered, you won’t see a recurrence of this issue on that device until you manually log out of Outlook. Outlook will keep you logged in. 

To check if your credentials are right:

  1. Open Outlook and click File
  2. You will already be on the Info tab. Find and click on the Account Settings button on the right-hand side.
Account information
  1. The Account Settings window will open. Select the Email tab and then highlight your account. Navigate to the Email tab and select your account. Find the Remove button with the X and click on it to remove your account.
Re-adding an email account can fix the Outlook cannot connect to server error
  1. Once your account is removed, close that window. Click Home from the top menu and log in with the right credentials. Double-check that the spelling, punctuation, and capitalization are correct. Now, you can check to see if you can connect to the Exchange server.

3. Turn Offline Mode off

Even if your credentials are correct and verified, Outlook will still have issues connecting if you’ve turned Offline Mode on. When Offline Mode is on, Outlook cannot connect to the Microsoft Exchange server. This means you will get the “Outlook cannot connect to server” error. 

To turn Offline Mode off: 

  1. Open Outlook and click on the Send/Receive tab on the top menu. 
  2. Underneath the Send/Receive tab, look for Work Offline. If it is surrounded by a darker gray background, then the Work Offline mode is on.
Work Offline mode enabled
  1. You can also check for Offline or Online status by checking the bottom of the Outlook window.
Working offline
  1. Click the Work Offline button in the ribbon menu to disable the offline mode. This is how it looks when offline mode is off:
Disable Work Offline mode to resolve the Outlook cannot connect to server error

4. Connect your computer to the Internet

Outlook has to have access to the internet, to reach the Exchange server. Make sure your computer is connected to the internet and that you can access external web addresses. Open a browser and check that a webpage will load. You should also check which WiFi or wired connection you are connected to. 

WiFi connection

If you are still unsure, you can run a speed test to check your upload and download. An internet connection with very poor connection speeds could also have issues connecting to the email server.

Make sure you have a stable internet connection when you see the Outlook cannot connect to server error.

5. Problem with Microsoft Exchange Server

Microsoft is a major brand, and their web services and products are highly stable. Microsoft’s cloud computing service, Azure, is responsible for providing high-quality, secure, and stable cloud servers for companies everywhere. Microsoft IT professionals and network engineers are experts in providing stable web and email servers. 

The likelihood that the Exchange server is down is low but not an impossibility. You can check if the Exchange server is experiencing an outage or issue by following these steps:

  1. Open Outlook and click File on the top menu. 
  2. Select Info on the left-hand side and then Account Settings on the right. If you see an orange icon on the left-hand side, there is an issue with the Exchange server.

You cannot do anything to fix the Exchange server yourself. Instead, allow Microsoft or your organization’s IT department some time to fix the problem with the Exchange server. When the icon is gone, you can attempt to connect to the server again. 

6. Outdated version

Microsoft often updates Outlook with regular safety and feature updates, as well as bug fixes. By default, Outlook is automatically set to install and apply any new updates. However, if you’ve manually selected to postpone an update, Windows will not automatically apply the update. This can leave your Outlook software outdated and lacking critical changes and bug fixes. 

To update Outlook:

  1. Open Outlook and click File on the top menu.
  2. Select Office Account from the left-hand side of the window. On the right-hand side of the screen, next to Office Updates, is a button called Update Options.
  3. Click Update Options to open the drop-down menu and select Update Now.
Update Office when Outlook cannot connect to the Exchange server
  1. After the update has been applied, restart your computer. Re-open Outlook and check if you are connected to the Exchange server.

7. Fix corrupted .PST files with ScanPST

Outlook builds a Personal Folder File or .PST file around your account and use of the Outlook software. If something corrupts the .PST file, it will need to be repaired, or this can prevent Outlook from connecting to the email server. 

Sometimes .PST files become too large and cause errors. To prevent the loss of your important data and restore the connection to the Exchange server, you can repair your Personal Folder File by using the built-in ScanPST utility. 

To fix corrupted .PST files, follow these steps:

  1. First, you need to find the location of the repair tool on your system. You’re looking for the scanpst.exe file in one of the following locations:
    • 32-bit Office 2016 and newer: C:\Program Files\Microsoft Office\Office16\
    • 64-bit Office 2016 and newer: C:\Program Files (x86)\Microsoft Office\Office16\
    • 64-bit Outlook 2016 and newer: C:\Program Files\Microsoft Office\Office16\
    • Office 365 (2016 package): C:\Program Files\Microsoft Office\root\office16\
    • 32-bit Office 2013: C:\Program Files\Microsoft Office\Office15\
    • 64-bit Office 2013: C:\Program Files (x86)\Microsoft Office\Office15\
    • 64-bit Outlook 2013: C:\Program Files\Microsoft Office\Office15\
    • Office 365 (2013 package): C:\Program Files\Microsoft Office\root\office15\
  2. Now you need to find the location of your PST file. You should find your personal folder at either:
    • Windows 10: drive:\Users\<username>\Roaming\Local\Microsoft\Outlook
    • Older versions: drive:\Documents and Settings\<username>\Local Settings\Application Data\Microsoft\Outlook
  3. Double-click on the scanpst.exe executable, and if the PST file is not automatically detected, you will need to type it now in the field “Enter the file name to be checked.”
  4. Select Start and allow Microsoft Outlook Inbox Repair to complete its check. 
Microsoft Outlook Inbox Repair
  1. The repair may take a few minutes. When it’s complete, you can restart your system and check if the Outlook issues are resolved.

You can find more information about ScanPST on Microsoft’s website.

8. Disable extensions

Typically, Outlook extensions have been verified by Microsoft to integrate without conflicts or security risks. But sometimes, extensions can cause unexpected issues. If you are getting the “Outlook cannot connect to server” error, it’s a good idea to disable your extensions. 

If Outlook can then access the Exchange server, you know one of your extensions is the culprit. You can enable them one at a time to identify the problematic extension. 

To disable your Outlook extensions:

  1. Open Outlook and click File on the top menu.
  2. Select Options from the left-hand side. The Outlook Options window will open. Click Add-ins on the menu to the left. 
Outlook Options
  1. At the bottom of the Add-ins page, find Manage: Com Add-ins. If Com Add-ins is not selected under Manage, do that now. Click Go
  1. Next to each extension, click to uncheck or disable that extension. Press the OK button.
  1. Your Outlook software is now free of any extensions. Restart Outlook and check to see if the Exchanger server connection error remains.

9. Create a new Outlook data file

Large data files can create lots of issues for Outlook. You can prevent errors and minimize data file size by asking Outlook to create a new data file. To do this:

  1. Open Outlook and click File
  2. You will already be on the Info tab. Find and click on the Account Settings button on the right-hand side. Select Account Settings from the drop-down menu. 
  3. In the Account Settings window, select the Data Files tab and click on your account. 
Outlook data files
  1. Click on Open File Location right below the main menu. Windows will open to that file location in File Explorer. Right-click on the file ending in .dat or the DAT File type. Copy and paste this file elsewhere for safe keeping. Then delete the .dat file.
Outlook data file location
  1. Close Outlook.
  2. Restart Outlook, and it will try to re-create the data file for you. Now check if Outlook has successfully connected to the mail server.

If you experience any issues or Outlook is not creating the new data file as expected, you can delete any new data file and replace it with the backup of the old data file.

10. Reinstall Outlook

When you’ve tried all the other solutions in this guide, you may feel like you are out of options. But sometimes, the issue is too deep or nebulous for you to fix yourself. Uninstalling Outlook and starting a fresh install can often fix this problem. 

To remove Outlook, you need to use the Windows Add or Remove Programs feature. Within the Microsoft subsection, you need to find Outlook and uninstall. Then reinstall the software and check to see if the problem remains. 

Outlook cannot connect to the server resolved

If you followed along with this guide, you have run through 10 different solutions to solve your “Outlook cannot connect to server” error. Not having access to your email can be disruptive, so it’s important to get it fixed as soon as possible. 

This error is most often caused by credential issues, outdated or corrupted software, outdated or corrupted .PST or data files, or a poor internet connection. If all else fails, you should talk to your company’s IT staff or contact Microsoft support.

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