How to Open Offline OST File in Thunderbird?

Looking for safe and easy solution to Open OST file in Thunderbird mail client, you are at right page. In this page you will come to know about how you can use your OST files in Thunderbird. Microsoft Outlook is mail application which stores its file in OST format and Thunderbird is mail client which uses file of MBOX format. So these both have different file format no need to worry you can easily use your OST file in Thunderbird. Before discussing the method let us discuss about OST file and MBOX file of Thunderbird in brief.

Offline Storage Table (OST)

OST file is offline copy of the user’s mailbox that is stored on the Exchange server. It enables the users to access all the data stored in the mailbox when the Exchange Server is not available. OST files stores complete mailbox including emails, contacts, drafts, notes, calendars etc.

Thunderbird (MBOX FILE)

Thunderbird is an email client which stores its file in MBOX format. There are multiple email clients which save their file in MBOX format and Thunderbird is one out of them. It is an open source and free email client which saves entire mailbox data easily. Thunderbird can be used on multiple platforms like Windows, Mac, Linux, and Ubuntu operating systems.

Reasons to Export OST file to Thunderbird:


Cross platform support: Thunderbird is a type of cross platform mail client that can be used on multiple platforms like Windows, Mac, Linux, and Ubuntu operating systems. Thunderbird is default client of Ubuntu.

Secure: It has high security features as compared to other email clients

Small user/Organization: If a user/organization has less dealing through Email then they may shift from a paid email client to freeware Email client.

User can use the Export option inbuilt in Outlook for exporting the OST file but it is not considered as the convenient method for migrating because this method does not assure conversion in secure manner. So you can use Third party tool for complete and accurate migration of OST files to Thunderbird email client. One best recommended tool which is easily affordable with all the advanced and required features is ‘Regain OST to PST converter’. This tool can migrate OST files without installation of Outlook.

How to convert OST files using OST to PST converter?

Conversion of OST mailbox is very easy by using Regain OST to PST converter. Using this tool you can convert OST file to MBOX/EML file format and the converted files can be easily accessed in Thunderbird. Steps to be followed for converting the OST file are:


1) Install and Run Regain OST to PST Converter on Windows Operating system

2) Click on Add file/Add folder and select the OST files

3) Take Preview of OST file before migration in other format

4) Select location for saving the file after conversion

5) Next from saving option select ‘save to MBOX/EML’ option

6) Click Convert, files will be exported shortly.


Additional Features of OST to PST converter

  • Instantly convert OST files in few clicks
  • No loss of data and maintains the original format of the data
  • Efficient to repair corrupt OST file and recover deleted or lost OST emails
  • Compatible with Microsoft Outlook 2019, 2016, 2013, 2010, 2007, 2003, 2000, 2002, 98 and 97
  • Export OST files in multiple formats PST, EML, MSG, MBOX, HTML, ICS, VCARD, Office 365, Live Exchange Server
  • Supports all windows edition i.e. Windows 10, 8.1, 8, 7, XP, Vista
  • Detailed preview of emails before conversion
  • Allow to Import OST data files to Office 365 account
  • Easy handling of bulky files
  • Download free trial version and Save 30 emails per folder at Free of cost


In above page we have discussed about how one can run his Outlook OST files in Thunderbird mail client. Data stored in OST format is important for every user so no one will like to compromise with their data. If anyone can compromise with his/her data than export option of Outlook can be used but first and last recommendation of every expert is using of third party tool. One can use reliable software i.e. “Regain OST to PST converter” this tool is very easy to use and provide with results in very less time.