Outlook Cannot Connect to the Server Error 0x80040115

  

Rollins Duke   
Published: June 3rd, 2025 • 8 Min Read

Outlook error 0x80040115 is a common connectivity issue that occurs when Microsoft Outlook cannot connect to the server. This error prevents from sending, receiving emails and also affects your workflow specially in business environments when Outlook is heavily used.

This error typically indicates a synchronized problem between mail server and Microsoft Outlook due to corrupted or outdated Outlook profile, connectivity issues, increase OST file size problem, faulty add-ons, antivirus or issues with Exchange server configuration.

Users may encounter this error when trying to send and receive emails, especially in environments where Microsoft Exchange is the backend mail server. Outlook shows error: Task reported error(0x80040115): This operation could not be performed because connection to the mail server is offline or Microsoft Outlook is retrieving data from Microsoft Exchange Server Error 0x80040115. This error mostly appears due to DNS or profile issues.

Common Reasons of Outlook Error 0x80040115

• One of the prime reasons is failure to send and receive emails. Outlook emails stay outbox independently or return a connection failure message.
• The Outlook application may become sluggish, freeze during synchronization, or hang when trying to access the mailbox, especially when it attempts to connect to the Exchange Server.
• Users might see pop-ups or warning messages stating that Outlook is having trouble synchronizing folders, usually followed by the 0x80040115 error code.

Primary Causes of Outlook Error 0x80040115

• A corrupted or outdated DNS cache can disrupt the resolution of server addresses, preventing Outlook from reaching Exchange Server.
• When Outlook data files become too large or corrupted, they can hinder the normal functioning of the application, leading to detect OST errors like 0x80040115.
• Some third party can interfere with Outlook performance, especially those that try to interact with server or modify send/recieve behaviour.
• A broken or incomplete Outlook installation may lack necessary performance, especially those that try to interact with server or modify send/recieve behavior.
• Fluctuating or weak connectivity is a major cause of Outlook failure to maintain stable connectivity with mail servers.
• If Microsoft Exchange server is experiencing downtime, misconfigurations or overload then Outlook reported error 0x80040115.

How to Fix Outlook Error 0x80040115?

Facing error 0x80040115 Outlook can be frustrating but you can resolve it by following the correct approach. Below is a comprehensive guide to fixing the error efficiency.

Method 1. Flush DNS Cache

1. Press Win+R and type CMD and hit Enter.
2. Type command ipconfig /flushdns.
3. Press Enter to successfully flush the DNS Resolve cache.

Method 2. Launch Outlook in Safe Mode

1. Press Win+R and type Outlook.exe/safe.
2. Hit Enter and Outlook will launch with minimal features.
3. Identify problematic add-ons by clicking on file and hit on Add-ons.
4. At the bottom set manage to COM Add-ons and click GO.
5. Uncheck unnecessary or unknown add-ons and relaunch Outlook to see changes.

Method 3. Disable or Remove Faulty Add-ons

1. In Outlook, navigate to file and click on Add-ons.
2. Use Manage dropdown to select COM Add-ins then click GO.
3. Uncheck all add-ins and relaunch Outlook.
4. enable them one by one to find the Culprit.

Method 4. Repair Outlook Installation

1. Click on the Control Panel and click on Programs.
2. Press Program and features and select Microsoft Office.
3. Press on Change and choose Quick Repair.

Method 5. Create A New Outlook Profile

1. Open the Control Panel and click on Mail(Microsoft Outlook).
   
2. Press on Show Profiles and click on Add and type name.
   
3. Setup Email configuration and always use this profile to make it default.

Method 6. Check and Improve Connectivity

1. Restart your modem/router.
2. Use LAN cable for connectivity.
3. Check speed to verify connectivity.

Method 7. Repair Corrupted Outlook Files

1. Locate C:\Program Files(x86)\Microsoft Office\root\Office16/ScanPST.exe
2. Run the tool and choose Outlook files as you want to repair.
   
3. Click on Start to begin repair and recover damaged files.
   

Alternative Method to Fix Outlook Cannot Connect to the Server(0x80040115)

If you have tried lots of manual methods but no one works then OST get dismounted from the server. So, you need to opt BitRecover OST to PST Converter as this software is capable of converting individual or batch Outlook OST files and also specially known for maintained results.