Outlook randomly saves email files as 0kb

Question

Hi,

We are experiencing an issue with Microsoft Outlook where one specific user cannot properly save emails. When the user tries to save an email (e.g., as .msg), Outlook randomly saves it as a 0 KB file.

This issue only affects one user. All other users in the same environment can save emails without any problems.

Here’s what we have already tried:

Deleted and recreated the PST file

Completely uninstalled and reinstalled Microsoft Office

Switched to the new Outlook experience (this seemed to fix the issue temporarily, but the problem returned)

Verified that no add-ins are installed

Additional information:

• The issue happens randomly
• It does not affect other users
• The problem occurs when saving emails locally
• Has anyone experienced a similar issue or knows what else we can check?

Could this be profile corruption, permissions-related, or something else?

thanks in advance

Answer 1

Hi Kyrylo-Tadei Krukenytskyi | KKR,

Welcome to Microsoft Q&A Forum! 

Have a good day and I hope you're doing well! 

Based on your description that it affects only one user, works temporarily in the "New Outlook" experience, and happens randomly, I agree with your assessment. This strongly points to a client-side corruption or a specific environmental conflict on that machine (Windows/File System level) rather than a server-side issue. 

Based on my research, please try the following troubleshooting steps in this order: 

1. Create a completely new Outlook Profile: You mentioned deleting the PST, but sometimes the corruption lies within the Outlook Mail Profile configuration (Registry/Cache) rather than the data file itself. 

• Go to Control Panel > Mail > Show Profiles > Add. 
• Configure the email account again in this fresh profile and set it as "Always use this profile". 
• Test saving an email here. 

Reference: Create an Outlook profile - Microsoft Support 

2. Test saving to a "Clean" Local Directory: We need to rule out long file paths or permission inheritance issues. 

• Create a simple folder directly on the C drive (e.g., C:\TestEmail). 
• Ask the user to save the email directly to this folder. 

This ensures the folder is strictly local, has no complex permissions, is not redirected, and is not subject to the 255-character path limit. 

3. Temporarily Disable OneDrive / Folder Redirection: This is a very common cause for 0 KB files. The process of saving a .msg file depends on stable local I/O. 

• In environments with OneDrive Known Folder Move (Backup for Desktop/Documents), the sync engine might attempt to upload the file handle immediately after it is created (at 0 bytes) but before Outlook finishes writing the data stream. This conflict results in an empty file. 
• Please Pause OneDrive syncing and ensure the user is not saving to Desktop or Documents if those folders are being synced. Then test again. 

4. Test on a different Windows User Profile: If all the above fail, the corruption might be located in the Windows User Profile itself (Registry hives or User-specific permissions). 

• Please try logging into that specific machine with a different Windows user account (or create a new local test user). 
• Setup Outlook and try to save the file. 
• If it works on the new Windows user, the original Windows User Profile is likely corrupted and needs to be recreated. 

Reference: Create a local user or administrator account in Windows - Microsoft Support 

I hope this helps you narrow down the cause and gives you some reasonable insights for troubleshooting, at least partially. If you have any concerns or questions, or if I misunderstood or was unclear about anything, feel free to reach out. 

---

If the answer is partially helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".    

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.  

Answer 2

It sounds like the issue with the specific user saving emails as 0 KB files could be related to several factors, including profile corruption or issues with the Outlook data file. Since you've already tried deleting and recreating the PST file, uninstalling and reinstalling Microsoft Office, and switching to the new Outlook experience, here are a few additional steps you might consider:

1. Check for Corruption: Since this issue affects only one user, it could be due to corruption in their Outlook profile. You can try creating a new Outlook profile for this user and see if the issue persists.
2. Permissions: Ensure that the user has the necessary permissions to save files in the location they are trying to save to. Sometimes, permissions issues can lead to problems with saving files.
3. Antivirus/Firewall Settings: Occasionally, security software can interfere with Outlook's ability to save files. Check if any antivirus or firewall settings might be blocking this action.
4. Updates: Ensure that Outlook and Windows are fully updated. Sometimes, updates can resolve unexpected issues.
5. Check Sync Issues: If the user is using Cached Exchange Mode, check the Sync Issues folder for any errors that might indicate problems with the data file.

Since the problem occurs randomly, it might take some time to identify the root cause. If the issue continues, consider reaching out to Microsoft support for more tailored assistance.

---

References:

• Email messages aren't sent when you use a template file in Outlook 2010
• You may experience application pauses if you have a large Outlook data file