Outlook Running Slow – Enhance Its Performance with 12 Solutions

Outlook Running Slow – Enhance Its Performance with 12 Solutions


Have you ever felt your email is loading forever or your calendar events are crawling on your screen? If you’re one of the many people using Microsoft Outlook for email, you might have faced these problems. But don’t worry! This blog will guide you through simple ways to fix the Microsoft Outlook Running Slow and freezing issue. We’ll talk about things like cleaning up old emails, adjusting some settings, and even doing tech magic behind the scenes. All our tips are easy to follow – you’ll be an Outlook speed demon in no time!


Reasons Why Outlook is Running Slow

Many factors are responsible for the Outlook running slow; these include: 


  • Overloaded Outlook data file (.pst or .ost).
  • Unnecessary or problematic add-ins can slow down Outlook.
  • Not using the latest Outlook version.
  • A large number of emails are in your inbox.
  • Numerous large attachments can affect speed.
  • Other software interfering with Outlook.
  • Potential malware infection.
  • Disk fragmentation.
  • Problems with server synchronization.
  • Non-updated computer drivers.
  • Pending operating system updates.
  • Issues with the Outlook installation.



How to Fix Microsoft Outlook Running Slow Issue

The following are the solutions to fix the slow functioning of Outlook:


Solution 1: Launch Outlook in Safe Mode and then Disable Add-ins

When Outlook running slow, the first thing you should do is launch Safe Mode and disabling the add-ins to enhance its performance. Safe Mode opens Outlook without accessing add-ins, identifying if these are causing the slowdown. Additionally, when you disable the unnecessary add-ins, your Outlook load will reduce and help it run more efficiently. The following are the steps:


  1. Firstly, close Microsoft Outlook if it’s currently open.
  2. Secondly, press the Windows key + R to access the Run dialog box.
  3. Now, type outlook /safe (without quotes) in the box, and then hit Enter. Outlook will launch in Safe Mode.
  4. Once in Safe Mode, click on the File tab and select Options.
  5. In the Options window, select Add-ins from the left pane.
  6. At the bottom of the window, you’ll see Manage: COM Add-ins. Click on the Go button.
  7. In the COM Add-ins window, uncheck any add-ins you don’t need, then click OK.
  8. Lastly, restart Outlook normally to see if it’s running faster.


Solution 2: Archive Old Emails

Archiving the old emails can resolve your Outlook running slow issue. This will reduce the load on Outlook and allow it to function faster. AutoArchive function allows you to automatically move older emails to a separate PST file, thus improving Outlook’s performance by reducing your mailbox size. The following are the steps:


  1. Open Microsoft Outlook.
  2. Select the File tab and click Options.
  3. Select the Advanced tab.
  4. Under AutoArchive, click on AutoArchive Settings.
  5. Set the frequency of AutoArchiving and define the age of items to be archived.
  6. Choose the folder for archived items to be stored, then click OK.


Solution 3: Update Windows

Updating Windows ensures you have the latest security and performance improvements. A fully updated system can help Outlook and other applications run smoothly. Regular updates address known bugs and issues, which can prevent Outlook running slow issues. Update with the following:


  1. Click on the Start button
  2. Then select Settings.
  3. Select Update & Security.
  4. Select Windows Update.
  5. Click on Check for updates. If any updates are available, then Windows will proceed to install them automatically.
  6. After the update, restart your computer to ensure all updates are properly implemented.


Solution 4: Update Outlook

Just like keeping your Windows operating system up to date, keeping your Outlook application updated is essential. Microsoft periodically releases updates for Outlook to introduce new features, fix known bugs, or improve performance. If you’re running an older version of Outlook, updating it could potentially resolve issues causing Outlook running slow. Go with the following means:


  1. Open Outlook and click File.
  2. From the File menu, click on Office Account or Account, depending on your version.
  3. Under Product Information, click on Update Options.
  4. Click on Update Now. If any updates are available, they will be downloaded and installed. Outlook might need to be restarted to complete the update process.
  5. After the update, check if Outlook’s performance has improved.


Solution 5: Tweak Junk Email Options

Outlook Spam Filter is a resource-consuming feature that checks incoming messages for signs of spam. It may slow down Outlook, mainly when you receive a large number of emails. By adjusting the filter level, you can enhance Outlook’s speed. The following are the steps:


  1. Firstly, launch Microsoft Outlook.
  2. Then, click on the Home tab located on the top navigation bar.
  3. In the Delete group, choose the Junk dropdown
  4. Now, click on Junk E-mail Options.
  5. After that, in the Junk E-mail Options window, under the Options tab, you will see four levels of automatic filtering. Select a level that suits you. Note: selecting a lower level will use less system resources.
  6. Lastly, click Apply then OK to save the changes and close the window.


Solution 6: Disable Hardware Acceleration

Hardware Acceleration is a feature where an application will offload specific computing tasks onto specialized hardware components in the system, enabling greater efficiency than software running on a general-purpose CPU. But sometimes, it may cause Outlook running slow. In such cases, disabling Hardware Acceleration can improve the performance of Outlook. Go with the following means:


  1. Open Outlook and click on File.
  2. From the drop-down menu, click on Options.
  3. In the Outlook Options window, click on the Advanced tab.
  4. Scroll to the Display and then mark Disable hardware graphics acceleration.
  5. Click on OK and then restart Outlook to apply the changes.


Solution 7: Compress the Outlook File

The larger your Outlook file, the slower Outlook will run. This is especially true for .pst and .ost files, as they store all your emails, contacts, calendars, and other data. Compressing these files can help speed up Outlook. Here’s how to do it and fix Outlook running slow issue:


  1. Launch Microsoft Outlook.
  2. In the left pane, right-click on the root folder (usually named with your email address or Outlook Data File) and select Data File Properties.
  3. In the properties window, click on the Advanced button.
  4. From Outlook Data File, choose Compact Now.
  5. A dialog box will appear, showing the compacting process. Once finished, click OK in the two open windows.
  6. Close and reopen Outlook to notice the change in speed.


Solution 8: Disable Antivirus

Sometimes, antivirus software can interfere with Outlook and cause it to run slower. Temporarily disabling the antivirus might speed up Outlook. Remember, this increases vulnerability to threats, so do it judiciously and consider other solutions first. Do it with the following: 


  1. Locate your antivirus program in the search.
  2. Right-click the antivirus icon, then look for terms like disable, stop, or exit.
  3. If prompted, pick how long to disable the antivirus.
  4. Restart Outlook and check if the performance has improved.


Solution 9: Repair the Outlook Application Files

Outlook’s application files can sometimes get corrupted or damaged due to various reasons like improper shutdowns, system errors, or virus attacks. Such corruption can cause Outlook running slow. Microsoft Office has a built-in repair tool that can diagnose and fix these issues, potentially improving the performance of Outlook. Repair with the following:


  1. Close Outlook.
  2. Go to the Control Panel.
  3. Click on Programs and Features, locate then Microsoft Office from the list, and click on Change.
  4. Select Quick Repair in the dialog box and Repair. 
  5. Once the process is done, restart your computer and open Outlook.


Solution 10: Create a New Outlook Profile

Sometimes Your Outlook stuck on loading profile which contains settings and configurations for your Outlook account. If this profile gets corrupted, it could cause Outlook running slowly. Creating a new profile will provide a fresh set of settings for Outlook, which might resolve the slow performance issue. After creating it, you must set it as the default profile for Outlook. The following are the steps:


  1. Close Outlook.
  2. Go to the Control Panel.
  3. Click on Mail, then on Show Profiles.
  4. Click on Add to create a new profile, enter a name, then follow the prompts to add your email accounts.
  5. Back in the Mail window, under When starting MS Outlook, utilize this profile, select Always use this profile, and pick the new profile from the dropdown.
  6. Click OK, then open Outlook.


Solution 11: Repair the PST Data

The PST file is a data file that Outlook uses to store your emails, attachments, and other data. Over time, this file can develop errors that might cause Outlook running slowly. These errors can be fixed using Outlook’s built-in Inbox Repair Tool (scanpst.exe), potentially improving the performance of the software. Repair with the following:


  1. Close Outlook.
  2. Use Windows Search to find scanpst.exe. The exact location depends on your version of Outlook.
  3. Run scanpst.exe, click Browse, then navigate to the PST file. By default, it should be in Documents\Outlook Files.
  4. Click Start then Repair if errors are found.
  5. Once the repair is complete, reopen Outlook.


Solution 12: Perform a Clean Install

Sometimes, despite all your troubleshooting efforts, Outlook may continue to perform slowly. This could be due to deep-rooted issues that are difficult to resolve. In such scenarios, performing a clean install of Outlook could be beneficial. A clean install involves completely uninstalling and reinstalling Outlook, eliminating corrupt files, and installing fresh ones. Follow the given steps to perform and fix Outlook running slow issue:


  1. Click on the Start button.
  2. Go to the Control Panel.
  3. Select Programs and Features, find your version of Microsoft Office in the list, and click on Uninstall. Follow the prompts to uninstall the program.
  4. Restart your computer.
  5. Go to the Microsoft Office website and download the latest version of Office.
  6. Run the installer and follow the prompts to install Office. Be sure to select Outlook when choosing which components to install.
  7. Once the installation is complete, launch Outlook. You’ll need to set up your email account(s) again.
  8. Check if Outlook’s performance has improved.


Note: Remember to back up any critical data before uninstalling Outlook, as a clean install will remove all Outlook data files.



Summing Up

Microsoft Outlook’s performance issues can largely be resolved by following the above-mentioned strategies. While each situation might require a different solution, these steps offer a comprehensive approach to fix Outlook running slow issues. However, if you want to talk to the Experts for an advanced solution, contact our Support Team to get the answer. Happy Emailing!




Q: Why is Outlook running slow and not responding?

A: Outlook not responding or run slow for various reasons like a large mailbox, many add-ins, outdated software, or corrupted files. Hardware issues, antivirus software, or conflicts with other software can also cause these problems.


Q: What to do if Outlook is running slow?

A: To speed up a slow Outlook, you can try steps like launching Outlook in Safe Mode and disabling add-ins, archiving old emails, updating Windows and Outlook, adjusting junk email options, disabling hardware acceleration, compressing the Outlook data file, disabling antivirus temporarily, repairing the Outlook application and PST files, creating a new Outlook profile, and if necessary, performing a clean install of Outlook.


Q: How to improve Outlook performance?

A: Improving Outlook performance involves keeping the software and your system updated, managing your mailbox effectively by archiving or deleting old emails, disabling unnecessary add-ins, tweaking various settings, and keeping your PST or OST files error-free. A periodic clean-up of the mailbox and careful management of add-ins can significantly boost Outlook’s speed. If these steps don’t work, consider creating a new Outlook profile or reinstalling the software.