What is OST File Extension, and How to Open OST file?

Nowadays, every working professional, whether its employee or a student, uses Outlook for their daily task. Outlook, when configured with Exchange Server, creates OST files. But what if the Exchange Server is down or you don’t have internet connectivity? 

There is no need to worry because OST (Outlook Storage Table) is always there to ensure that your folders and files do not get lost permanently.

What is the OST file, and when does Outlook create it?

OST stands for outlook storage table, and it allows user to continue their work even in offline mode. It even helps to recover all the mailboxes that disappear due to an issue with the exchange server. 

When you are using Outlook with Exchange Server and Cached exchange mode is enabled, Outlook creates a local copy of the mailbox item in OST file format. Similarly, if you disable the cached exchange mode, Outlook will directly access the data from Exchange Server, i.e., No OST file will be created.

OST file is a type of folder used as an offline storage file. The primary purpose behind this was to let the users read their outlook files even when there is no internet available. Many people have to read their essential mails, but because of the unavailability of the internet, they cannot do their work, which becomes a barrier when working on something. 

How does OST File be Helpful?

The user can access the OST file for reading or writing a mail, adding or searching a contact, creating new tasks, etc., while being offline to the internet. The point to keep in mind is that any changes made while being offline will not be saved. I.e., any updates by the user will not be synchronized with the account unless the user gets a proper connection to the internet. 

Storage Location of OST File

  • Follow the steps given below to know the location of the Outlook OST file.
  • Click the ‘File’ tab in Outlook.
  • Then click on ‘Account Settings’
  • Under that, there will be another option of ‘Account Settings.’ Click on that.
  • Click on the option of ‘Data Files.’
  • Click on an account and then click ‘Open Folder Location.’

Here is the location to directly navigate to the location of the OST file:                  \Users\user\AppData\Local\Microsoft\Outlook

Size and Structure

The older version, i.e., Outlook 2002 and earlier editions, used the ANSI format encoding. Also, this limited the file structure to a maximum of 2 GB.

The Size limit of OST file in Latest versions of Outlook is 50GB which you can modify as per your needs from registry settings

Applications for Opening OST Files

Here is a list of apps that you may try to open the OST file:

  • MailsDaddy Free OST Viewer Tool
  • MailsSoftware Free OST Viewer
  • a2zMigrations for OST to PST
  • SysBud OST to PST Converter

How to Open OST files in Outlook?

In Microsoft Outlook, the data are classified into two types: ost and pst. Here is the article for Difference Between OST and PST File Format

When OST files do not open or are damaged, you must convert them to .pst files. We present to you the complete step-by-step process of the same. Moreover, You don’t always need Outlook, Microsoft 365, and other apps to check the data stored in your ost file. 

You can easily open the Converted PST file into Outlook by double-clicking on it.

Are you looking for the perfect solution for Outlook Storage Table-related problems?

Reading this full blog will solve all your doubts about the ost file folder and how to deal with a sudden network connectivity issue. We have provided a complete solution for ost-related queries. Still facing some issue or trying everything but failing to recover the content? Comment below your problem and mention the name of the device and the os system you are using; our team will reach you as early as possible with all the possible outcomes.

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