email error 0x80040115

Hi @Gary Antone, 

Thank you for reaching out and sharing your experience regarding the error in classic Outlook. 

I can totally understand the inconvenience of not able to send and receive emails for you daily work. According your concern, the issue could be due conflicting Outlook cache or connection between Outlook and Exchange. To resolve the issue, please follow these steps: 

1. Recreate the PST file manually  

• Press Windows + R key to open the run dialog box, type control, then press Enter to open the Control Panel.  
• Click on Mail.  

• Click on Show Profiles in the Mail Setup.  

• Tap on the Add button to add a new file. Input the name and click OK.  

• Click on Mail in the control panel and select the Data Files tab.  
• Select the new Outlook profile from the list, then click the Set as Default option.  
• Exit the Control Panel and restart tor PC, then check if the error persists.  

2. Repair Microsoft Office  

• Press Windows + I keys to prompt Windows settings.  
• Click the Apps menu and select Installed apps.  

• Locate Microsoft Office in the apps list, click the menu against it, and select the Modify option.  

• Select Online Repair from the new menu and click the Repair button.  

3. Open Outlook in safe mode and troubleshoot add-ins 

• Press Windows + R, enter Outlook/safe into the Run dialog box and click on the OK button. 
• Go to File > Options > Add-ins. 

• Disable all installed add-ins. Close Outlook and relaunch  
• Try to send an email. If it works, enable one add-in and retry the email sending. 
• Continue activating add-ins one by one until you receive the 0x80040115 error. When this happens, you can know that the last add-in you enabled is the culprit. 

4. Flush device DNS records 

• Open Command Prompt as an administration. 
• Enter the following command in the Command Prompt window and press enter: Ipconfig/flushdns 

I hope this information is helpful. Please follow the steps above and let me know if it works for you. If not, we can continue working together to resolve the issue.  

Thank you for your patience and understanding. If you have any questions or need additional assistance, please don’t hesitate to reach out so I can continue to support you. If you found the response useful, please consider marking it as accepted, as this may help other community members who are looking for similar guidance.  

I look forward to continuing the conversation.

If you have extra questions about this answer, please click "Comment". 

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Error 0x80040115 in Outlook commonly indicates a problem communicating with the Exchange server or a damaged Outlook data file. If there is no usable .ost file, rebuild or repair the local data file and Outlook installation.

Try these steps in order:

1. Rebuild the .ost file (Exchange account)
   1. Close Outlook.
   2. In File Explorer, go to:
      • Windows Vista and later: C:\Users\<alias>\AppData\Local\Microsoft\Outlook
   3. If the folder is hidden, enable Hidden items and File name extensions on the View tab.
   4. Locate the .ost file for the affected profile and either delete it or rename the extension to .old.
   5. Reopen Outlook; it will create a new .ost file and resynchronize from the server.
2. If Outlook reports problems opening the data file
   1. Close Outlook.
   2. Run the Inbox Repair Tool (SCANPST.EXE) as described in the documentation to diagnose and repair the Outlook data file (.pst or .ost). The tool checks for corruption and offers to fix it.
   3. After repair completes, start Outlook again with the same profile.
3. If problems persist after rebuilding/repairing the .ost
   • Repair Office from Apps and Features as described in the guidance for replacing damaged Exchange support files, then reopen Outlook and let it resync.

These steps address corruption or local profile issues that can cause send/receive failures and errors like 0x80040115.

References:

• Errors have been detected in your .ost file in Outlook
• Synchronization problems occur in Outlook and in Outlook Web App
• Repair Outlook Data Files (.pst and .ost)
• Issues when you synchronize your Exchange Server mailbox with your .ost file in Outlook