Outlook NST file and How to Import/ Open NST File in Outlook?

Updated On - December 26, 2023 by Nasir Khan | Reading Time: 5 minutes

Are you a regular user of Microsoft Outlook? If so, then I think you might be familiar with the PST and OST file formats and extensions. But have you ever heard of an NST file? Most users will say “no.” However, you should have some knowledge of every file format. This post is going to give you a clear concept of what an NST file is and how to create and open .NST formatted file in  MS Outlook.

What exactly is an .NST file format in Outlook?

Fundamentally, an NST is an Outlook data format that is saved on the desktop’s local disk once a subscriber sets up an Office 365 account in Outlook. Microsoft Outlook integrates the native edition of Office 365 and saves it on the device in a “Group Storage Table” (GST file) format.

The GST file was created to let users operate in an offline mode on Office 365, similar to how an OST file functions for MS Outlook. To clarify your concerns, both the OST and GST files are kept in a similar location.

Related Post: How to Open PST files in Thunderbird

Often, the NST file is used to save talks in teams and calendars, whereas the OST file is used to hold inbox contents as well as other directories. If one user connects to “Lotus Notes” through the Outlook Connector, NST files are created on the device’s local drive.

Do you know how to create an .NST file in Microsoft Outlook?

In general, once the Office 365 account is established in Outlook, an NST file is produced by default in all versions of Outlook (latest and older). However, follow the step-by-step procedure given below if you don’t have any idea about how to create an NST file.

  1. Start Outlook and navigate to the “Add Account” page, where you may enter your Office 365 email address and then press the “Connect” option.How to Open NST Files into MS Outlook
  2. Microsoft Outlook starts creating a new account when the getting things ready wizard appears. Sit tight for it to be completed.Steps to open NST file to Outlook
  3. You will be presented with a “Windows Security” wizard. Enter the password for the Office 365 account you’re using and press the “OK” icon.Step by step manual guide to Import NST Files into Outlook
  4. You will now see a “Mail Delivery Location” pop-up window. Hit ‘OK‘ to proceed with the procedure of creating Office 365 NST files in Outlook 2016 and earlier editions.Steps to open NST File in MS Outlook
  5. When you see the screen “Account setup is complete,” press the “OK” option.Free and easy guide to Open NST File tp MS Outlook
  6. The Outlook application commences retrieving mailbox items from the Office 365 account when you hit the “OK” option. Sit tight for the procedure to finish.Simpe and easy manual guide
  7. When the retrieval procedure is completed, the whole Office 365 email address list appears in the Outlook program. You have successfully produced the .NST formatted file in Outlook 2016, 2013, and earlier releases.

Where are the Outlook NST files located?

If you don’t know where the NST files are saved on your device and are looking for the exact location, then you can read out the steps as follows. After that, you will be able to find the path by yourself.

  • Click the right button over the Office 365 account and select the very last choice, “Data File Properties.”
  • Press the “Advanced” option and then OK.
  • Go over to the ‘Advanced‘ tab in the MS Exchange window immediately.
  • Next, underneath “Cached Exchange Mode Settings“, choose “Outlook Data File Settings” and press OK.
  • Copy the file location path from the file bar and shut it down by clicking OK.
  • Laden Windows Explorer instead of Outlook.
  • Put the copied file path into Windows Explorer’s URL path and erase the remainder section that appears after Outlook. And then press the enter key to go over the directory of the Outlook NST file.

In this way, you can get the exact path or location of the Outlook NST files in your device’s directory.

In MS Outlook, how do you open an NST file?

Because NST file formats are Office 365’s cached offline data, they are constantly in a quite inaccessible state. To see .NST files in the Outlook application, users must first convert NST to PST format and then import them into Outlook.

Now the question comes to how you can convert NST files into PST format. Actually, converting NST files into PST isn’t as easy as it sounds. It has some criticism as it isn’t readable. We would recommend using the Regain OST Converter software for this purpose. Follow the steps as follows:

  • Step 1. First, on your device, open the directory of the NST files (we have described how to find the location of NST files on your desktop. Check out the above phases).Manual Method to Open NST File to MS Outlook
  • Step 2. After locating it, click the right button on the NST file and click on the “properties” option.Best and easy way to Open NST File into MS Outlook
  • Step 3. Then, from the ‘General’ tab, change the .NST extension to the .OST. That’s all.

After that, you need to download and configure the OST file on your device. Then, with the help of this professional software, you can easily convert the .OST formatted files into .PST and open them in Outlook.

Free Download100% Secure Buy NowPrice: $39

In this way, you can open NST files in your Outlook. It’s an indirect way, but probably the easiest one as far as we know from our research.


In this blog, we discuss in detail what NST File is, how to create a .nst file in Microsoft Outlook, where it is located, and know how to open an NST file in Office 365. All the possible scenarios we describe here. I hope all the confusion has been solved regarding the NST file. If anyhow your NST file is corrupted due to oversize, you can fix this issue by using Regain OST Recovery tool.

Frequently Asked Questions

Ques1. How are the Outlook NST files different from the Outlook OST and PST file formats?
Ans. Outlook PST and OST files are used to store the entire data of an Outlook account. OST files are stored on the server, whereas PST files are stored in the local drive. On the other hand, NST files are used to save chat in teams and calendars.

Ques2. Can I use the Regain OST recovery tool to recover Outlook NST files and open NST file in Outlook?
Ans. Yes, you can use the Regain OST recovery tool to recover Outlook NST files and convert them into different file formats.

Ques3. I don’t have an Office 365 account in Outlook. Do I have NST files? If not, then why am I not able to access my OST file?
Ans. If you don’t have configure Office 365 account in Outlook then you’ll not have any NST files. The reason behind OST file is not accessible is that your OST file might be corrupt.

Ques4. How can I check the Regain OST recovery tool with my NST file without any investment?
Ans. We offer a free version of the tool for users so they can evaluate the tool’s skills and compatibility without spending a penny.


Author: Nasir Khan

I am Nasir Khan from India, working as a Content Developer in Regain Software. Here I am writing about our products and their updates. And writing some free solutions from converting emails or Cloud Migration process. We have tools like Email Converter, Emails backup and Cloud migration.

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