There can be multiple reasons for your Microsoft Outlook to stop responding.
The problem may occur when you open or close Microsoft Outlook, reply to an email, switch from folder to folder, or upload or download an attachment.
It happens often at the times when you are replying to an important email.
Let's look into some of the reasons that may cause Microsoft Outlook not to respond or freeze.
These include a temporary glitch; a third-party program that is running simultaneously with Microsoft Outlook; an Outlook add-in; in-progress synchronization; an over-sized PST file; antivirus program; IMAPExchange account; Outlook registry entries; and a virus or malware infection among others.
Now that you have become familiar with the possible reasons, let's move on to fix Outlook.
Case 1: Is it the first time your outlook stopped responding? If it is the first time your Outlook stopped responding, give this tweak a shot.
Open Task Manager either by pressing the Ctrl, Alt, Delete keys together or right-clicking anywhere on the taskbar.
Click the Processes tab, look for the Outlook.
exe process and select it, and hit the End Process button.
Close the Task Manager window.
Reboot your computer now.
When it has rebooted fully, open Outlook and check whether it is working or not.
Case 2: Third-party applications Close any third-party application that runs at the same time when Outlook runs.
Outlook should work fine after you close the program.
Antivirus software, firewall, add-in, plug-in, or toolbar are among a few of the third-party programs that can cause Microsoft Outlook to freeze.
Since security programs like antivirus, anti-spyware or firewall are designed protect your privacy and data from unauthorized intrusions and infections that often come via emails, they configure stringent security and privacy settings that sometimes prevent Outlook from sending or receiving emails or functioning properly.
To avoid these kind of Microsoft Outlook problems, reconfigure your security program to add Outlook and Outlook add-ins to the trusted zones.
If you lately installed an Outlook add-in (Microsoft or third-party) and after which Outlook stopped responding, disable it.
Check whether Outlook has started working or not.
If it has, update the Outlook add-in with latest updates and patches.
If Outlook still does not respond, uninstall the add-in and install another or a similar one from a different company.
There is a possibility that the particular add-in software was not written properly by its publisher.
Case 3: An oversized PST file Microsoft Outlook is designed to archive emails or other items automatically.
Archiving helps decrease the size of your mailbox and allows Microsoft Outlook to work properly.
Since archiving is a resource-hog process, Outlook can stop responding due to larger files, pending tasks like emails, and programs that run simultaneously with it.
Similar to archiving, synchronization is also a resource-hog process.
To avoid Microsoft outlook from stop responding.
let it finish its pending tasks.
Besides, do not make more clicks and do not start new tasks before starting archiving or synchronization.
An over-sized PST file (file that stores the entire Outlook data) or large mailbox can cause Outlook to stop responding.
To avoid this problem, archive your mailbox items regularly.
Delete the unnecessary files or attachments that are of no use any longer.
For an oversized .
pst file, divide it into multiple small .
pst files.
Yes, create several small .
pst files and divide your Outlook data into them.
Besides, regularly back up your .
pst files to avoid losing data due to virus or other problem.
Case 4: Problem with Registry Entries If the registry entries of your Microsoft Outlook have gone corrupt, it might not respond to your clicks.
You will need to repair the damage registry entries.
Download a free registry repair program from a trusted website and install it on your computer.
We do not recommend you to manually repair register entries as it is a risky and sensitive procedure.
If you wrongly change your registry, your computer may permanently crash.
So, repair them using a registry repair program.
Also create a system restore point before running the registry repair program.
Doing so will let you restore your computer to a previous state in case something goes wrong.
When done, open and run the program and fix the damaged registry entries.
Additional Info: If you have set up an auto responder or have scheduled some emails to be sent automatically, there is a possibility that your antivirus program may block them.
It is because some antivirus programs often consider auto-emails that are trying to be sent or downloaded as phishing, spam, or virus carriers and thus block them.
Besides, if you suspect that a virus-carrying email has caused your Outlook program to hang, look for it and remove it from your mailbox.
Open your antivirus program and update it with the latest virus and malware definitions.
Afterwards, run a full virus scan of your computer.
Delete any infected files that were brought in the scan.
We recommend that you update your antivirus program regularly.
The problem may occur when you open or close Microsoft Outlook, reply to an email, switch from folder to folder, or upload or download an attachment.
It happens often at the times when you are replying to an important email.
Let's look into some of the reasons that may cause Microsoft Outlook not to respond or freeze.
These include a temporary glitch; a third-party program that is running simultaneously with Microsoft Outlook; an Outlook add-in; in-progress synchronization; an over-sized PST file; antivirus program; IMAPExchange account; Outlook registry entries; and a virus or malware infection among others.
Now that you have become familiar with the possible reasons, let's move on to fix Outlook.
Case 1: Is it the first time your outlook stopped responding? If it is the first time your Outlook stopped responding, give this tweak a shot.
Open Task Manager either by pressing the Ctrl, Alt, Delete keys together or right-clicking anywhere on the taskbar.
Click the Processes tab, look for the Outlook.
exe process and select it, and hit the End Process button.
Close the Task Manager window.
Reboot your computer now.
When it has rebooted fully, open Outlook and check whether it is working or not.
Case 2: Third-party applications Close any third-party application that runs at the same time when Outlook runs.
Outlook should work fine after you close the program.
Antivirus software, firewall, add-in, plug-in, or toolbar are among a few of the third-party programs that can cause Microsoft Outlook to freeze.
Since security programs like antivirus, anti-spyware or firewall are designed protect your privacy and data from unauthorized intrusions and infections that often come via emails, they configure stringent security and privacy settings that sometimes prevent Outlook from sending or receiving emails or functioning properly.
To avoid these kind of Microsoft Outlook problems, reconfigure your security program to add Outlook and Outlook add-ins to the trusted zones.
If you lately installed an Outlook add-in (Microsoft or third-party) and after which Outlook stopped responding, disable it.
Check whether Outlook has started working or not.
If it has, update the Outlook add-in with latest updates and patches.
If Outlook still does not respond, uninstall the add-in and install another or a similar one from a different company.
There is a possibility that the particular add-in software was not written properly by its publisher.
Case 3: An oversized PST file Microsoft Outlook is designed to archive emails or other items automatically.
Archiving helps decrease the size of your mailbox and allows Microsoft Outlook to work properly.
Since archiving is a resource-hog process, Outlook can stop responding due to larger files, pending tasks like emails, and programs that run simultaneously with it.
Similar to archiving, synchronization is also a resource-hog process.
To avoid Microsoft outlook from stop responding.
let it finish its pending tasks.
Besides, do not make more clicks and do not start new tasks before starting archiving or synchronization.
An over-sized PST file (file that stores the entire Outlook data) or large mailbox can cause Outlook to stop responding.
To avoid this problem, archive your mailbox items regularly.
Delete the unnecessary files or attachments that are of no use any longer.
For an oversized .
pst file, divide it into multiple small .
pst files.
Yes, create several small .
pst files and divide your Outlook data into them.
Besides, regularly back up your .
pst files to avoid losing data due to virus or other problem.
Case 4: Problem with Registry Entries If the registry entries of your Microsoft Outlook have gone corrupt, it might not respond to your clicks.
You will need to repair the damage registry entries.
Download a free registry repair program from a trusted website and install it on your computer.
We do not recommend you to manually repair register entries as it is a risky and sensitive procedure.
If you wrongly change your registry, your computer may permanently crash.
So, repair them using a registry repair program.
Also create a system restore point before running the registry repair program.
Doing so will let you restore your computer to a previous state in case something goes wrong.
When done, open and run the program and fix the damaged registry entries.
Additional Info: If you have set up an auto responder or have scheduled some emails to be sent automatically, there is a possibility that your antivirus program may block them.
It is because some antivirus programs often consider auto-emails that are trying to be sent or downloaded as phishing, spam, or virus carriers and thus block them.
Besides, if you suspect that a virus-carrying email has caused your Outlook program to hang, look for it and remove it from your mailbox.
Open your antivirus program and update it with the latest virus and malware definitions.
Afterwards, run a full virus scan of your computer.
Delete any infected files that were brought in the scan.
We recommend that you update your antivirus program regularly.