What is OST file – its advantages, disadvantages and conversion to PST file

If you use Outlook to manage your emails, it is most necessary to secure your Outlook files or to keep their archive in PST file. In this article, I will explain some basics of OST file and the way to convert OST file to PST format for protecting your important emails.

What is OST file?

OST, an abbreviation of Outlook Storage Table, allows users to continue their task even if Outlook is disconnected from Exchange server and users are in offline mode. For example, you can write new emails, save them in drafts, read the existing ones etc. Once the Exchange server comes back to action, you are automatically connected to it and it starts sending and receiving of all pending emails itself. In this way, you remain in sync with the exchange.

Moreover, OST file helps in recovering the lost mailboxes in case of any damage to the Exchange Server or even if the server is down. OST file is actually a carbon copy of the mailbox lying on Exchange Server and this carbon copy is stored at computer's hard drive. Therefore, damage to the Exchange Server does not affect OST saved at hard drive. Here is a bit about the advantages and disadvantages of OST file.

Also See: Newly Convert OST to PST Has Full Solution for Most OST Files Errors


OST files are beneficial in case of limited, unreliable, and vulnerable Internet connectivity.

It is not mandatory to stay connected with Exchange Server while performing the tasks. Users can continue their work without waiting for connectivity as OST does it all itself. However, connectivity to Exchange Server is a mandate if new emails have to be sent.

OST files are advantageous, if exchange database is corrupt and reaches in unrecoverable state. Now user can retrieve data from OST stored at hard drive. However, the process is time consuming because administrator will have to collect all the mailboxes owned by the exchange database. Besides this, to recover mailboxes from an OST, user needs to convert OST file to PST file because Outlook can fetch data from PST file, even if the respective email profile is deleted.

For most users, some emails are most important and have to be recovered anyhow. In such cases, OST files are most useful.


The disadvantage of OST is that it helps only for the email profile it belongs to. In case of email profile damage or deletion, the OST is also of no use. In such situation, it becomes difficult for MS Outlook to fetch data.

Well, if user needs to recover mailbox from an OST file, an efficient conversion to PST file is necessary. There are numerous commercial OST to PST converting software already available in market today. These softwares offer competency, efficiency, reliability and better performance and they can be purchased online without any hassle.


Guest Author: Chandana15 May 2015

Use InFixi OST to PST Software to solve your all outlook OST file problems.

Download Infixi OST File Converter Tool.
Run .exe and see how to repair OST file data.
Recover Outlook OST emails In seconds.
Convert recovered OST data into multiple formats.
Split recovered PST file data upto 5GB.
Save OST file data as Outlook PST format with all OST file mailbox items.

Guest Author: Henry08 Mar 2016

Simon Cortez,

Is it a free tool? I am looking for some free tools to convert OST files. Please let me know if you know any free tools that comes with no catch.

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