PST File Documentation

Overview

Feature Value
Format Name Outlook Personal Information Store File
File Extension .pst
MIME Type application/octet-stream
Developed by Microsoft
Initial Release 1996
File Structure Binary
Maximum File Size 50GB (Outlook 2010 and later versions), 20GB (Outlook 2007), 2GB (Outlook 2003 and earlier versions)
Encryption Support Yes (optional)
Compression No
Unicode Support Yes (from Outlook 2003 onwards)
Content Type Emails, attachments, calendar events, contacts, tasks, notes
Usability Data storage and backup for Microsoft Outlook
Main Usage Storing Outlook personal data including emails and attachments
Accessibility Accessible via Outlook or compatible software
File Location on Windows %USERPROFILE%Local SettingsApplication DataMicrosoftOutlook
Backup Importance High, contains important personal and business information
Data Recovery Capability High, with appropriate tools
Compatibility Primarily compatible with Microsoft Outlook
File Integrity Check ScanPst.exe (Inbox Repair Tool)
Cloud Storage Compatibility Can be stored in cloud storage, however, direct cloud editing is not supported
APIs or Libraries Limited third-party support due to proprietary format