What is an .OST file?

What is an .OST file?

As all users of Microsoft Exchange Server are aware, they can either work with their mailbox on the server in the online mode or the cached mode. The biggest advantage of working in the cached mode is that it allows users to continue working with data from the mailbox as though they were still connected to the server even though they may be offline. Outlook creates an offline storage file, OST file and then copies the content of the mailbox on the server into this file. Mobile users can then access this copy of the mailbox offline. To take full advantage of this feature, users should know about the different configurations of the Cached mode setting.

Though you can set the various configurations for Outlook manually, if you are a system administrator looking after an entire Exchange organization, you would be better off if you just applied the settings at the group policy level. The OST group policy settings can be located by first going to the main User Configuration menu and then looking at the Administrative Templates. From Microsoft Office Outlook 2007, select Tools and then Account Settings, from where you can click on Exchange. While there may be other options, you should look at the group policy setting for the OST files. Before making changes, you should be aware that some of the changes could cause serious damage to OST files and that there should be a backup option to quickly recover OST data.

.OST files are a product of Microsoft Outlook, and contain your offline e-mail data.

Working offline means you have access to your data in situations where a connection to your e-mail server cannot be established. To make this possible, your data must be saved locally on your workstation.

.OST files are a format used by Microsoft Outlook to save your offline data on your workstation. The next time you have a connection and Outlook can communicate with the e-mail server, your data from the .OST file can be synchronized with what’s on the server.

An OST file (.OST) is an offline folder file in Microsoft Outlook. Offline folders make it possible for the user to work offline and then to synchronize changes with the Exchange server the next time they connect. The ability to work offline is useful in environments with limited or unreliable connectivity.