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Read time 12 minutes

Summary: Several free methods are discussed below for converting OST files to PST files, including exporting mailboxes as a PST file, using archiving to save OST emails to PST, and the drag & drop method.
However, for a hassle-free OST to PST conversion experience, we highly recommend utilizing the Kernel for OST to PST Converter tool.

OST files are the binary copies of Exchange Server mailbox folders. These files get created automatically when mailbox folders are first accessed, and they’re used to store messages, calendar items, and other data for offline access. When you connect to your Exchange mailbox, the OST file is synchronized with the server copy of the mailbox.

However, what if you need to access your Exchange mailbox from a remote location or you don’t have an active internet connection? In such cases, you can convert your OST file into a PST file which can be accessed offline. Today, we are here to discuss different methods that can be used to convert OST files with ease. We will also provide step-by-step instructions on how to use these methods.

Some beneficial scenarios to convert OST files to PST are here

As OST files are the data files of Exchange accounts connected in Outlook, they are helpful in multiple situations like the following:

  • A few user mailboxes get deleted from the Exchange server
  • Want to back up a few Exchange mailboxes (before the deletion of mailboxes)
  • An Exchange user wants to rebuild his corrupt OST file, but the user has some unsaved data in the OST file
  • The Exchange accounts are inaccessible due to corruption, but users want their emails urgently.
  • To re-establish email communication during Exchange downtime or unavailability
  • If you’re switching from one email client to another and your new email client doesn’t support OST files, you’ll need to convert the OST file to PST in order to access your old emails.
  • If your email account has been corrupted and you can no longer access it. In this case, converting the OST to PST will allow you to access your old emails and potentially recover any lost data.

There are multiple methods to convert any OST file to PST, provided you can log in to Outlook with the same Exchange profile. Some native methods to convert OST to PST are presented here:

Method 1: Export mailbox as a PST file

Login to Outlook with the Exchange account that was used to create the OST files. And to export the OST mailboxes to PST, follow the simple procedure as given here:

  1. Go to Files >Open & Export and click Import & Export.Import & Export
  2. Select Export to a file; then click Next.Select Export to a file
  3. Select the second option—Outlook Data File (.pst)—and click Next.Select PST file
  4. Select the folder(s) which you want to export and click Next.Select the folder to exportNote: You have the option to include subfolders as well.
  5. Browse the location where you want to save the new PST files and choose an option regarding the duplicate items.Note: There is an optional choice to provide a password to the PST file, but you can easily move ahead without choosing it.

Method 2: Use archiving to save OST emails to PST

By enabling the Auto Archive method in Outlook, you will be able to save the items of the OST file in a separate PST file. This method helps you to keep the size of your mailbox manageable. When there are many older messages and you do not require them in the mailbox, you can put them in the archive folder easily. This will reduce the size of the mailbox. Follow the simple steps to enable auto archiving in Outlook.

  1. Launch the Outlook application, go to File and click Options.
  2. Go to Advanced and click Auto Archive Settings.Auto Archive Settings
  3. Now select the number of days in which you want to run auto archiving. Select the folder to save the archived file; also, provide the archiving options and finally click OK.Select the folder to save the archived file With this, mailbox items from your OST file will be saved to the PST file as per your archiving settings.

Method 3: Use drag and drop method to move limited data.

If you want to move only a selected data from your Outlook account, then you can create another data file in Outlook and drag-&-drop data from other accounts. If the size of your OST file has reached to its maximum size limit, then you can transfer data to another file and lower the data file size.

  1. First, create a new data file in Outlook. Click New Email and expand More Items. Choose Outlook Data File.create a new data file
  2. Choose Outlook data file (.pst) and click OK.Choose Outlook data file
  3. Save the PST file in an accessible folder and a new data file is created. Then, you can select some data from the older account and try to drop in the new account. It will ask if you want to move the folder inside the new account. Click Yes.Save the PST fileThe data will be moved quickly, and you can access new content there.

Method 4: Convert OST files without Exchange profile or server connectivity

Kernel for OST to PST is a professional tool that can freely convert 25 items from each OST folder to PST. Its advantage is that it can convert offline OST files to PST without an Exchange profile or Exchange Server connectivity. It has a highly user-friendly interface that lets the user select OST file(s), recover items including the deleted ones, and convert them to PST format. Also, it can convert multiple OST files to PST at a time.

Features of the utility

Some of the other key features of the converter include:

  • Supports all versions of Microsoft Outlook including 2003, 2007, 2010, 2013, 2016, & 2019.
  • Converts encrypted and password-protected OST files
  • Allows you to split large sized PST files into smaller parts
  • Preserves all data including emails, contacts, tasks, notes, etc. during conversion
  • Provides a preview of all converted data before saving it

Let’s see the working of the tool to easily convert OST to PST files:

  1. Open the OST conversion tool. It will open a wizard to select single or multiple OST files. Select the OST file from its location.Select the OST file
  2. When the tool displays the OST file content, you can choose a folder and view its content in the preview pane. To convert the OST file into PST, click the Save option on the toolbar.Save option on the toolbar
  3. To save in PST, click PST file (MS Outlook) as the Output type.save in PST
  4. Select and apply the required filters – From, To, Subject, Folder Name, Item Type, and Date rangeSelect the filters
  5. You have the option to split the PST file after a certain size. Provide the required details.Select option to split the PST
  6. Browse the destination and provide the required details. Lastly, click Finish.Browse the destination
  7. When the conversion is complete, the tool shows a message showing the PST file name and its location.conversion is complete

You can manually convert OST files to PST only when you are using Outlook with the original Exchange account. But the software converts even inaccessible OST files into PST format without the original Exchange profile and Exchange Server connectivity. It can convert OST files created by webmail (IMAP) accounts too. Also, it provides many advanced filtering and saving options.


Now that you know about these free methods to convert OST files to PST , give them a try and see which one works best for you. However, if you want the quickest and most reliable solution, then we suggest using our recommended tool. It’s fast, easy-to-use, and top rated by many users. If you have any questions about these methods or need help converting your file, please reach out to us and we would be happy to assist you.

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