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).
Software that open ost file
OST file extension - Microsoft Outlook inbox off-line folder
What is ost file? How to open ost files?
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
Updated: December 20, 2024
The default software associated to open ost file:
Company or developer:
Microsoft Corporation
Microsoft Outlook is a professional e-mail management tool and personal information manager distributed with the Microsoft Office suite. Outlook integrates the e-mail application, calendar, task manager, contact manager, and note-taking into one application.
Company or developer:
Microsoft Corporation
Microsoft Outlook for Mac is e-mail client and personal information manager distributed with Microsoft Office for Mac. Outlook for Mac contains email, calendar, address book, task list, note list managers in one application. Microsoft Outlook for Mac is a successor of Microsoft Entourage for Mac.
List of software applications associated to the .ost file extension
Recommended software programs are sorted by OS platform (Windows, macOS, Linux, iOS, Android etc.)
and possible program actions that can be done with the file: like open ost file, edit ost file, convert ost file, view ost file, play ost file etc. (if exist software for corresponding action in File-Extensions.org's database).
Hint:
Click on the tab below to simply browse between the application actions, to quickly get a list of recommended software, which is able to perform the specified software action, such as opening, editing or converting ost files.
Software that open ost file - Microsoft Outlook inbox off-line folder
Programs supporting the exension ost on the main platforms Windows, Mac, Linux or mobile. Click on the link to get more information about listed programs for open ost file action.
Microsoft Windows:
Main software associated with ost file by default:
Microsoft Outlook
Other suggested software:
PstViewer Pro (EML Viewer Pro)
