"I'm new to using Outlook for work, and it's been an interesting learning experience so far. However, I've encountered a frustrating issue recently. Whenever I attempt to reply to an email in Outlook, the application crashes. I've tried restarting both Outlook and my computer, but the problem persists. If anyone has insights into what might be causing this and how to resolve it, I would greatly appreciate your help."

Outlook crashes when replying to an email, and one possible reason for this is a corrupt delivery location or folder where the message is supposed to be delivered. This is particularly relevant if your account is configured with POP3. However, if your situation doesn't involve POP3, there are other potential reasons for this issue. Let's explore some of these possible causes:

The error statement that may popup while replying to an email is “Outlook not responding.”

Why does Outlook crash while replying to an email?

Outlook may crash while replying to an email because the delivery location or the folder where the message is going to be delivered is corrupt. This means you are trying to reply to a folder that does not exist. But you will only face this issue, if your account has a POP3 configuration. But if this is not the case with you, then we are going to mention the most possible reasons. Here are some of the reasons that may lead to this issue:

  • Outdated version of Outlook.
  • Recently added add-ins.
  • Any other instances of Outlook that are running in the background.
  • Bulky mailboxes.
  • Fault in Office programs.
  • The conflict between antivirus program and Outlook.
  • Corrupted user profile.
  • Any other program is conflicting with Outlook.
  • Corrupt, damaged, or broken Outlook data file
  • Redirection of AppData folder to a network location

These are the potential reasons that could lead to this issue, and we've provided some known solutions that might help you resolve it quickly. For instance, if you have multiple instances of Outlook running in the background, you can try closing all of them and see if that resolves the problem. Additionally, you can attempt the following solutions for an immediate fix:

  • Update Outlook
  • Update Windows
  • Update MS Office
  • Close all the other programs running in the background

Please attempt all the solutions provided above and see if any of them resolve your issue. In some cases, you can use the advanced diagnostics offered by Outlook to automatically fix the problem. To do this, follow these steps:

  1. First, you will need to install the Outlook Advanced Diagnostics tool (https://aka.ms/SaRA-OutlookAdvDiagnostics)
  2. Once you have properly downloaded and installed the software, run it on your system by giving Run permissions.
  3. Now, a report will be generated which will have the list of issues found after the scan.
  4. Click on the Detailed View tab to know the configuration details of Outlook, Windows, and your computer. You can review the settings and know the causes of the problem.

If you have attempted the previously mentioned methods and are still unable to determine the cause and resolve the issue, we recommend reading further in this blog for a more comprehensive solution.

How to Fix Outlook Crashes while Replying to an Email?

Here we are going to mention some of the solutions that may work for you.

  • Run Outlook in Safe Mode:- Running Outlook in safe mode may help you to know if the add-ins were causing the issue. For this, follow the below-mentioned steps:
    1. Start with pressing the Win + R key.
    2. As the window opens, type Outlook /safe and press Enter.
    run Outlook in safe mode

    Once done, you will enter Safe mode; if you are able to compose an email in safe mode, then add-ins are the cause of the issue. To disable add-ins, follow the steps:

    1. Open Outlook and click on the File option.
    2. Now, select Manage Add-ins and disable them.
    select Manage Add-ins

    Once done, open Outlook again and check if the problem is solved.

  • Make a new user profile :- As we have mentioned that a corrupt user profile may also be the culprit behind this error. So, let's try creating a new user profile and see if it works. For this, follow the below mentioned steps:
    1. Go to the Control Panel and click on the Mail option. make new user profile
    2. Now, select the Show Profiles option. show profile
    3. In the new mail window, click on the Add button. add button
    4. Now type a name under the Profile Name option and click on OK.
    5. Setup the email account and check if the problem is solved now.
    If you are still facing the issue, try the next method.
  • Fix Office Programs :- Outlook crashing when replying to an email can sometimes be caused by issues with Office programs. In such cases, it's a good idea to try repairing the Office programs. Follow these steps to do so:
    1. In your windows go to Settings and select Apps from the option given there.
    2. Then select Apps & features option from the Apps menu.
    3. Now, in the search tab, search for office and select MS Office.
    4. Now, click on Modify to proceed.
    5. In the next step, check the Repair option and click on Continue.
    6. Once the repair process id over, open Outlook and check if you still face the issue.
  • Check for Antivirus :- If you're experiencing problems with Outlook crashing when replying to emails, it might be due to conflicts with your antivirus software. To determine if this is the issue, try temporarily disabling your antivirus software and see if the problem persists. If the issue goes away after disabling the antivirus, you should add an exception for Outlook in your antivirus settings. Once you've done that, re-enable your antivirus software, and Outlook should work smoothly without crashing.
  • Fix Outlook Data File :- If you suspect that a corrupted or damaged Outlook data file is causing the crashing issue, your best course of action is to repair it using Kernel for Outlook PST Repair. This tool is well-known for its ability to fix various forms of corruption and damage in PST files. It's designed to handle multiple PST files simultaneously, regardless of their size or the extent of corruption. Importantly, the tool ensures that the original file and its structure remain intact while resolving the issues. For guaranteed results, we recommend using this tool. You can try it out by using the free version, which allows you to save up to 25 items per folder.


Outlook is a powerful email client with numerous features, but it can occasionally be prone to instability. We've explored various methods to help you resolve the issue of Outlook crashing when replying to emails. Hopefully, one of these solutions has worked for you, and you can enjoy a smoother Outlook experience. Additionally, if you encounter PST-related issues in Outlook, consider using our recommended tool to fix them easily. This tool can repair corrupt or damaged PST files and save them as healthy PST files. It offers a free trial version for repairing and previewing recovered data, allowing you to assess its effectiveness before purchasing the full license.