Give the right information about OST and PST file. Benefit, differences and other aspects of Outlook OST and PST file.

Restoring Outlook Emails from an OST after Deleting the Mailbox

OST to PST Conversion process easily get emails after deleting the mailbox

How to get Outlook emails from OST file?

By use of third party email recovery solution or manually method Outlook client can easily restore Outlook emails from damage or unreadable OST file.

OST to PST Conversion Process

It is a modern technique which can easily repair orphan OST file as well as convert an offline OST file into PST file.

Outlook Oversized OST File Problem

I would like to suggest useful tool to easily split oversized OST file.

Friday, 13 May 2016

Why We Need To Convert OST Files To Outlook PST?

Most of the users of MS Outlook are quite aware of two types of file formats i.e. OST and PST files. PST files (Personal Storage Table) are the main storehouse of all the data stored in Outlook whereas OST files (Offline Storage Table) contains the replica of data stored in Exchange server. OST comes into existence when the cached mode is enabled from Outlook allowing user to work offline without Mail server. Any changes made will get itself synchronized when connected with the Exchange Server. The blog will be discussing the reasons why we need to convert OST files to Outlook PST file.

Need of Conversion from OST File to PST

The main reason why users prefer to convert their Exchange OST mailbox to PST file is the several issues of OST file that makes the OST file inaccessible or corrupted. Some of the causes that lead to the conversion of OST to PST file are as follows:
  • Issue of Exceeding OST Size Limit
    Size limit of OST file varies with different Outlook versions. In Outlook 2007, size limit supported was 20 GB, which was increased to 50 GB in 2010/2013 versions. Usually, the maximum default size limit is set to 20 GB, which is why performance of Outlook slows down when it reaches or exceeds this size limit.
  • Orphaned State of OST file
    Each OST file is bound to particular Exchange Mailbox and any modification made is continuously synchronized to Exchange Server. When the Exchange Mailbox is dismounted/deleted from the server, the OST file will become inaccessible leading to orphaned state.
  • Synchronization Problems
    It arises if there is any interruption while the OST file is being synchronized with the Exchange Server. Since the OST file is encrypted, decryption key of the Outlook profile needs to be matched with the one in Exchange Server. If it does not, OST file will face synchronization problem making file inaccessible.
  • OST Bound to MAPI Profile
    Since OST file is bound to a particular MAPI profile, its access can be only done when the user log in and authenticate using the profile that was originally used to create an OST file. In case of authentication failure, client will restrict user to open Exchange OST file and its contents.
  • Corrupted OST File
    OST file may be corrupted due to power failure during synchronization, virus attack, improper handling of OST file, damaged hard drive/local storage where the OST file was stored, etc. The OST file in corrupted state may lead to inaccessibility and loss of contents in it.

How to Convert OST to PST

As discussed above, the issues in OST file makes the conversion of OST to PST file necessary. However, Outlook does not support direct conversion of OST to PST file. To repair the damaged OST, an inbuilt utility scanost.exe can be used, which is now replaced by scanpst.exe for repair of both OST and PST files. This method is used only to repair slightly damaged OST file and does not convert OST to PST. Therefore, a reliable way for easy conversion of OST to PST file is possible with the help of a third party tool, OST to PST Converter. It has the ability to convert all the data items like emails, contacts, calendars, etc. in Offline OST file to Outlook PST file, keeping the original formatting intact after conversion. The tool also supports recovery of data from corrupted OST file and save OST mailboxes to Office 365 account.


The blog has been aimed to focus on various issues associated with Exchange Offline OST file and the need for conversion of OST files to Outlook PST files. It further defines a solution through which user can effortlessly convert OST files irrespective of their states to healthy PST file using OST to PST Converter software.