How Do I Fix A Not Implemented Error in Outlook?

Are you seeing the “Not Implemented error in Outlook” whenever you try to send an email? Sometimes even simple actions like hitting Reply All or clicking Send/Receive can trigger this frustrating message.

The good news is that this issue isn’t as mysterious as it seems. It typically happens because something in Outlook’s background isn’t working properly often a faulty add-in or a corrupted PST file.

In this guide, we’ll walk you through clear, step-by-step solutions to help you fix the problem and get Outlook running smoothly again!

Outlook “Not Implemented” Error Explained: What It Really Means

The “Not Implemented” error in Microsoft Outlook often appears when you try to do simple tasks like replying to an email, sending a message, or using the Send/Receive option. When this message pops up, Outlook is basically telling you that it can’t complete the action because something inside the application isn’t functioning correctly.

This issue isn’t tied to one specific version either. It can appear in Outlook 2007, 2010, 2016, 2019, Outlook 2021, and even newer editions.

Despite the vague wording, the meaning is straightforward: Outlook has run into a problem. Something in your setup whether it’s an add-in, account profile, configuration setting, or the PST file has become corrupted, misconfigured, or is simply malfunctioning.

Now let’s break down the common reasons behind this error.

Common Causes of the Outlook “Not Implemented” Error

Several underlying issues can trigger this Outlook error. The most common ones include:

• Problematic or outdated add-ins that interrupt normal Outlook functions.
• Corrupted Send/Receive settings (SRS file) that break mail synchronization.
• Damaged Outlook profiles that stop key actions from working.
• Incomplete or faulty Office/Outlook installations causing essential features to fail.
• Failed or incompatible Outlook updates that introduce unexpected errors.
• Multiple Outlook versions installed, leading to system conflicts.
• Corrupted PST data files, which can block sending, receiving, or opening emails.

These issues often combine to trigger the “Not Implemented” message.

FIXED: Outlook “Not Implemented” — Step-by-Step Fixes

Below are the most reliable fixes, ordered from easiest to more involved. First, try Safe Mode to confirm add-ins are the problem, if Outlook works in Safe Mode, an add-in is almost certainly the cause.

1) Turn off problem add-ins (fast and often fixes it)

Faulty or outdated add-ins commonly trigger the “Not Implemented” message. Disable them, then re-enable one-by-one to find the troublemaker.

• Close Outlook.
• Start Outlook in Safe Mode to confirm add-ins are involved: press Windows + R, type outlook.exe /safe, and press Enter. (Or hold Ctrl while opening the Outlook icon and confirm Safe Mode.)
• If Outlook works in Safe Mode, go to File → Options → Add-ins.
• At the bottom, choose Manage: COM Add-ins and click Go.
• Uncheck every add-in and click OK.
• Close Outlook and open it normally. If the error is gone, re-enable add-ins one at a time, restarting Outlook after each. When the error returns, the last enabled add-in is the culprit keep it disabled or update/remove it.

2. Repair Microsoft Outlook (Fix Corrupted Program Files)

If Outlook’s core files are damaged or didn’t install correctly, features like Reply, Forward, or Send/Receive may stop working and trigger the “Not Implemented” error. Instead of reinstalling the entire suite, you can use Microsoft’s built-in repair tool to fix these issues quickly.

• Tick Windows + R, type appwiz.cpl, and hit Enter to open Programs and Features.
• Locate Microsoft Office in the list (or Microsoft Outlook if installed on its own). Right-click and select Change.
• Choose Quick Repair and click Repair to let Windows fix common issues.
• If the error persists, return and select Online Repair for a more complete rebuild of Office.

Note: Online Repair needs internet access and can take a bit longer.

• Restart your computer after the repair and open Outlook again to check if the error is resolved.

This fix works especially well if the issue appeared after a Windows update or an Office upgrade.

3. Create a New Outlook Profile

A damaged or misconfigured Outlook profile is another common cause of the “Not Implemented” error. Setting up a fresh profile gives Outlook a clean environment, which often resolves the issue immediately.

• Open the Control Panel and search for Mail.
• Click Show Profiles, then select Add. Enter a name for the new profile.
• Follow the on-screen steps to set up your email account. Outlook will auto-configure the settings.
• Go back to Show Profiles and under “When starting Microsoft Outlook, use this profile,” select Prompt for a profile to be used. Click OK.
• Launch Outlook and choose the newly created profile. Try sending, replying, or forwarding a message.

If everything works normally, you can set this new profile as the default. If the error remains, continue with the next solution.

4. Delete the SRS File to Fix Send/Receive Issues

Outlook saves your Send/Receive settings in a file with the .srs extension. When this file becomes corrupted, Outlook may fail to send, reply, or sync properly often resulting in the “Not Implemented” error. Removing the file forces Outlook to create a clean version.

1. Close Outlook completely.
2. Press Windows + R, type %appdata%\Microsoft\Outlook, and press Enter.
3. Find the file named Outlook.srs and delete it.
4. Restart Outlook. A fresh SRS file will be created automatically.
5. Try sending or replying to an email again. If it works, the corrupted SRS file was the cause.

5. Repair a Corrupted PST File

A damaged Outlook data file can also trigger the “Not Implemented” error. Outlook stores your emails, calendars, contacts, and other mailbox items in PST (or OST) files. When these files become corrupted, essential features may stop working.

Microsoft provides a built-in repair utility called ScanPST.exe, but before you use it, keep in mind that many users have reported data loss after running the tool. ScanPST attempts to fix errors by removing items it cannot repair, which means corrupted emails, notes, or attachments may be permanently deleted.

If you want a safer alternative, you can use a professional tool like BitData Migration Outlook Converter. This software is designed to repair even severely corrupted PST files while preserving all your mailbox data.

Why Choose BitData Migration PST Converter?

• Simple, user-friendly interface no technical skills required
• Repairs corrupted PST files and rebuilds them into a new, healthy PST
• Recovers all mailbox items (emails, attachments, contacts, tasks, calendars, notes, etc.)
• Suitable with Microsoft Outlook 2021, 2019, 2016, and previous ranges

Using this tool ensures your data stays safe and intact during the repair process.

If you still want to use ScanPST.exe, follow these steps:

1. Close Outlook completely.

2. Locate the ScanPST.exe tool (path depends on your Outlook version):

• Outlook 2016 / 2019 / 2021: C:\Program Files (x86)\Microsoft Office\root\Office16\SCANPST.EXE
• Outlook 2013: C:\Program Files (x86)\Microsoft Office\Office15\SCANPST.EXE

3. Run SCANPST.EXE, click Browse, and select your PST file.

• Default PST location: C:\Users\<YourUsername>\Documents\Outlook Files\

4. Click Start to begin the scan. If errors appear, click Repair.

5. Once completed, open Outlook again and check whether the error is resolved.

Conclusion

The “Not Implemented” error in Outlook can be frustrating, but the solutions listed above usually resolve it quickly. Keeping Outlook updated and maintaining regular backups of your mailbox can also help prevent similar issues in the future.

If none of the fixes work and Outlook still refuses to function properly, your PST file may be severely corrupted. In that case, using a reliable repair tool like Outlook PST File Converter is your best option. It can safely restore your data and get your mailbox working again without the risk of losing important emails or attachments.