BreviSoft OST to PST Converter is a professional-grade desktop application that converts intact and accessible Outlook OST files into fully usable PST, EML, MSG, MBOX, PDF, and HTML formats — without requiring a live Exchange or Microsoft 365 connection. Whether you are migrating mailboxes, switching email platforms, or archiving emails for compliance, BreviSoft delivers a smooth, zero-data-loss conversion experience with no technical overhead.

Core features

Complete mailbox conversion

Converts emails, attachments, contacts, calendars, tasks, notes, journals, and drafts from healthy OST files — preserving the entire mailbox structure intact.

Multiple export formats

Save converted data as PST, EML, MSG, MBOX, PDF, HTML, or vCard — giving you total flexibility over how and where the data is used.

Direct migration to live mailbox

Migrate OST data directly into Exchange Server, Microsoft 365, Office 365, or G Suite without intermediate file conversion steps.

Bulk batch processing

Load and convert multiple OST files simultaneously in a single operation — ideal for enterprise IT teams managing large-scale mailbox migrations.

Smart date and folder filters

Apply granular filters by date range, email subject, sender, folder name, or item type to selectively migrate only the data you need.

Preview before conversion

Browse and preview emails, attachments, contacts, and calendar items from the loaded OST file before initiating the conversion process.

Additional capabilities

• Maintains original folder hierarchy during conversion

• Preserves embedded images, attachments, and inline content

• Supports Unicode and multi-language mailboxes

• Converts OST without MS Outlook installation required

• Auto-detects and loads OST files from default locations

• Split large PST output files by size (1GB–50GB)

• Supports ANSI and Unicode PST file formats

• Compatible with all Outlook versions (2003–2021/365)

• Maintains email metadata: date, to, from, CC, BCC

• Removes duplicate emails during conversion (optional)

• Generates detailed conversion log reports

• Works with orphaned OST files after profile deletion