What is NST File Format? How to Open .nst File in Outlook?

Admin | Email Conversion email migration How to's Software Technology | 3 minutes read | Last updated on January 29th, 2024,

MS Outlook is popular and most used application across the globe. Users are quite aware of PST file i.e. Personal Storage Table and OST that stands for Offline Storage Table file to save mailbox database. However, there is one more file type supported by Microsoft Outlook 2019/2016/2013/2010/2007 storage file. Therefore, the main aim of the segment is to make users understand about NST file and how to open .nst file in Outlook?

What is NST File? Where it is stored?

The file with .nst extension automatically created by MS Outlook 2016 and earlier versions when a user configures its profile with Office 365 account and thus creates Office 365.nst file. Another possible scenario that creates .nst file is when a user make use of Outlook Connector for IBM Domino add-in to synchronize Lotus Notes data via Outlook. Moreover, NST file is similar to OST Outlook data file type. It also used to store all folder items such as contacts, emails, tasks, calendar and more.

NST – Technical File Description


Location of NST File

In MS Windows XP –

C:\Documents and Settings\%user_name%\Local Settings\Application Data\Microsoft\Outlook\

In MS Windows Vista, Windows 7, 8, 10 –


Now, if a user is carrying orphan NST file on a local system and want to extract its data in Outlook then it became hectic process to perform for users because NST file is accessible only in originally created profile. Thus, the possible solution to view NST file data in Outlook is by converting NST  file to PST format that can be opened in any Outlook account on any machine without hassle.

How to Open .nst File in Outlook?

In order to import NST file to PST, no manual method is available that a user can implement. So, to execute the same, reliable and effective solution exists i.e. NST file to Outlook app, currently introduced in the online market. Moreover, there is another old perfect utility i.e. OST to PST Converter that has the capability to copy NST file to PST in just few clicks. Once the process is completed, users will find the resultant file with accurate data integrity and folder structure. The GUI of the tool is understandable as technical and novice users can use the application to transfer NST data to PST. Users can download and use the application on any version of Windows OS.

Steps to open .nst file in Outlook:

Note: Before initiating NST file to PST conversion procedure, it is recommended to replace .nst extension with .ost file extension. After that, you can load the same on the tool easily.

Step 1. Now, first download and launch the software on Windows PC.

launch ost to pst tool

Step 2. Click Select File(s) and load OST file by making use of Add Files, Add Folders or Load Outlook Profiles.

add OST file

Step 3. After selecting the required file, software will scan its items and display them with checkboxes on the left software pane. A user can select a checkbox of desired folder and perform selective conversion.

select data items of OST

Step 4. Choose PST option by navigating to Saving Options button.

choose saving option

Step 5. Set options to get PST file as per need i.e. Create Separate PST, PST Split, Ignore System Folder Hierarchy, Change Language etc.

set options

Step 6. Click on Convert and start the process. Once the process gets finished, a message will appear on the screen “Conversion Completed Successfully”. Click OK to exit.

process completed


NST file is another file type of Outlook which is created when Outlook is configured with Office 365 account or when a user tries to access Lotus Notes via Outlook Connector. As lot of users are not aware of NST file. Thus, in the write-up we have covered “what is NST file” and “how to open .nst file in Outlook”. The .nst file is similar to other formats of MS Outlook. One can access NST file only in Outlook configured Office 365, it does not support other apps. So, if a user wants to retrieve NST file data on another computer, then it is better to open .nst file in Outlook by using the tool discussed above.