OST

Microsoft Outlook inbox off-line folder
File type: Various data file, Microsoft Office file
An ost file extension is used for Microsoft Outlook Offline Folders files. The ost files are used to store e-mail messages and other data download from an Microsoft Exchange server. Microsoft Outlook Offline Folders files are very similar to Outlook personal folders files (.pst files).
What is ost file?
File type category:
Various data file
Microsoft Office file
Date updated: December 20, 2024
The ost file extension is associated with Microsoft Outlook, a personal information manager, which is part of Microsoft Office, developed by Microsoft Corporation.
The ost file stores e-mail messages and other data saved by the application from an Exchange server or other mail server using IMAP protocol.
The ost files are very similar to the *.pst personal folder files, but do not support large file sizes.
The ost files are created when the "Use Offline Folders" option is checked in Outlook and are stored on the hard drive instead of the e-mail server.
The default location of ost files are:
Windows Vista, Windows 7, Windows 8, Windows 10
\Users\user\AppData\Local\Microsoft\Outlook
Windows XP or Windows Server 2003
\Documents and Settings\user\Local Settings\Application Data\Microsoft\Outlook
How to open ost file?
Use Microsoft Office Outlook to open/import Microsoft Outlook inbox off-line folder files.
How to convert ost file?
Kernel for Exchange OST Recovery can recover emails from OST files and then converts them PST format using Microsoft Exchange 5.0, 5.5, 2000 and 2003.
Suggested software to open ost file:
Associated software actions with the ost file
Software applications that can open ost files:
Microsoft Outlook (Microsoft Windows)
PstViewer Pro (EML Viewer Pro) (Microsoft Windows)
Microsoft Outlook for Mac (Apple macOS / Mac OS X)
Software applications that can edit ost files:
Microsoft Outlook (Microsoft Windows)
Microsoft Outlook for Mac (Apple macOS / Mac OS X)
Software capable of saving ost files:
Microsoft Outlook (Microsoft Windows)
Microsoft Outlook for Mac (Apple macOS / Mac OS X)
Software apps that create ost files:
Microsoft Outlook (Microsoft Windows)
Microsoft Outlook for Mac (Apple macOS / Mac OS X)
Software apps that import ost files:
Microsoft Outlook (Microsoft Windows)
SysTools OST Recovery (Microsoft Windows)
PstViewer Pro (EML Viewer Pro) (Microsoft Windows)
Microsoft Outlook for Mac (Apple macOS / Mac OS X)
Software apps that export ost files:
Microsoft Outlook (Microsoft Windows)
Microsoft Outlook for Mac (Apple macOS / Mac OS X)
Software apps that recover ost files:
Kernel for Exchange OST Recovery (Microsoft Windows)
Advanced Exchange Recovery (Microsoft Windows)
Software applications that handle other tasks involving ost files:
Microsoft Office (Microsoft Windows)
PstViewer Pro (EML Viewer Pro) (Microsoft Windows)
Microsoft Office for Mac (Apple macOS / Mac OS X)
Office 365 (Multiplatform)