OST or Offline Storage Table is an Outlook data file, which is created when you set up an Exchange or IMAP account in MS Outlook on Windows. To convert Exchange or IMAP OST to PST file format via Outlook Import/Export Wizard, Outlook users must be logged in to their Exchange or IMAP account in the Outlook with their original MAPI profile.

But if you can’t log in or access your Exchange or IMAP account in Outlook, you cannot convert or export OST mail items to a PST file. This is due to the security and encryption that connects the Exchange mailbox, OST file, and MAPI profile together. In such cases, you can use an OST to PST converter software such as Stellar Converter for OST to convert OST file to PST.

Here we’ve explained both methods to export or convert Exchange or IMAP OST file to PST format.

Method 1: Using Outlook Import Export Wizard

This method works when Outlook is accessible, and you can log in and access your mail items via MS Outlook. Skip this method if, for any reason, you cannot log in to your Outlook account. In such a case, simply follow Method 2.

Alternatively, you may follow these Outlook guides to troubleshoot various Outlook errors and access your Exchange or IMAP profile.

Steps to convert IMAP or Exchange OST to PST in Outlook 2013, 2016, and 2019,

  • Open Microsoft Outlook and navigate to ‘File>Open & Export>Import/Export’

Import/Export Outlook Data File

  • From the options, choose ‘Export to a file’ and click ‘Next
  • MS Outlook Import/Export Wizard From Create a file of type: list, choose ‘Outlook Data File (.pst)’ and click ‘Next
  • Export OST to PST To convert entire OST file data to PST, choose the Exchange or IMAP email account, click ‘Include subfolders’ checkbox and then click ‘Next

TIP: You may also select and convert specific mail folders from OST file to PST.

  • Select Outlook Mail items for export Click on the ‘Browse button to choose a save location on your system and then click ‘Finish’

Browse PST save location You may password-protect the converted PST file to prevent unauthorized access or import. This step is optional.

  • You may click ‘OK’ without entering the password

Enter a password to protect PST

This starts exporting OST mailbox items to PST Data File.

Exporting OST to PST

NOTE: You may need to enter the password one more time.

Export Password-protected PST

IMPORTANT NOTE: This method can’t export meta-data such as folder properties, blocked list, and message rules to the PST file.

Steps to convert IMAP or Exchange OST to PST in Outlook 2010,

  • Open Outlook 2010, navigate to File>Open and click on Import

Outlook 2010 import export

  • Choose ‘Export to a file’ from the options and then click Next

export to a file

  • Select Outlook Data File (.pst) and click Next

Outlook data file .pst

  • Choose email folder, check the box Include subfolders and then click Next
  • Click Browse to choose a save location and then click Finish

choose browse location to save pst Again, you may choose to password-protect the converted PST file.

Method 2: Using Stellar Converter for OST Tool

Stellar Converter for OST is an OST to PST converter tool for Windows. It helps you convert accessible, inaccessible, and orphaned Exchange or IMAP OST files to PST and other file formats such as RTF, HTML, MSG, EML, and PDF. You can also convert an encrypted OST file to PST by using this software.

Steps to convert OST to PST by using the software:

  • Download, install and launch Stellar Converter for OST software
  • Click ‘Browse to choose the OST file or click the ‘Find’ button to locate all OST files stored on your system
  • Choose an OST File Click on the ‘Convert’ button
  • Scanning OST file After conversion, click ‘OK
  • OST file scan complete After the scan, you can preview all the emails

Preview mail items after the scan


  • Click on the ‘Save Converted Filebutton under ‘Home
    save converted file


  • Choose ‘PST from the ‘Save Options. You may also choose to compact or split PST while saving from ‘Advance Options

choose PST file format

  • Click ‘Browse’ and choose a location where you want to save the PST. Click ‘OK.

converting OST file to PST


You can easily convert Exchange or IMAP OST to PST in Windows via Outlook Import/Export wizard. This helps you create mailbox backup and migrate mailbox items to different Outlook account. However, you cannot convert OST to PST if Exchange or IMAP account is inaccessible and when you can’t log in to your Outlook profile. In such a case, the only option is to use a reliable OST to PST converter tool such as Stellar Converter for OST.

By using the software, you can convert an inaccessible, orphaned or encrypted OST to PST file. You can also split large PST files to create a backup and avoid corruption. The software also lets you convert OST to other formats such as HTML, RTF, EML, MSG, and PDF.

By using the Technician version of the software, you can also directly export the OST to a Live Exchange server or Office 365 account.