Prism Migration Suite — PST & MBOX 2026 Engine

Dedicated standalone migration engines for Outlook PST and Unix MBOX formats supporting 17 destination targets.

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Inspiration

Enterprise mailbox migration has always been plagued by corrupted attachments, stripped email headers, and system freezes. Traditional migration scripts depend heavily on Microsoft Outlook MAPI wrappers, meaning administrators cannot easily extract or convert orphaned .pst or Unix .mbox files on modern workstations or cloud environments. We set out to engineer two completely standalone, forensic-grade conversion engines capable of streaming gigabytes of email data with zero data loss.

What it does

Prism Migration provides two dedicated standalone desktop software engines:

1. Prism PST Converter Tool (Outlook to 17 Formats)

Parses Outlook .pst files independently of Microsoft Outlook or Exchange Server:

  • Supported Inputs: Unicode and legacy ANSI PST files, orphaned OST, EML, and MSG records up to 100GB+.
  • 17 Output Targets: PDF/A, MBOX, EML, MSG, HTML, MHTML, RTF, DOC, TXT, JSON, CSV, EMLX, Split PST Archive, Microsoft 365, Gmail, IMAP Server, and Yahoo Mail.
  • Auto-Split: Automatically splits large 50GB PST files into 2GB, 5GB, or 10GB chunks.

2. Prism MBOX Converter Tool (MBOX to 17 Formats)

Batch-converts Unix RFC 4155 MBOX mailboxes into 17 target formats:

  • Supported Inputs: Mozilla Thunderbird, Apple Mail, Google Takeout, Postbox, Eudora, and cPanel Maildir.
  • 17 Output Targets: Microsoft Outlook PST (Unicode), PDF, EML, MSG, HTML, MHTML, RTF, DOC, TXT, JSON, CSV, MBOX (Clean), EMLX, Microsoft 365, Google Workspace, IMAP Server, and Yahoo Mail.
  • Architecture: Native Apple Silicon (M1–M4) and Windows 11 Universal Binaries.

How I built it

  • Designed custom low-level binary parsers to deserialize Outlook PST Node B-Trees (NBT) and Block B-Trees (BBT) directly from disk.
  • Implemented strict RFC 822 MIME decoders to preserve multipart boundaries, inline graphics, and header threading (Message-ID, In-Reply-To, Date, CC/BCC).
  • Built a Producer-Consumer multi-threaded pipeline with SQLite checkpointing for resumable, interrupted batch migrations.

Challenges I ran into

  • Handling proprietary Microsoft Outlook encryption and password-protected PST headers without access to native Windows MAPI32.dll.
  • Preventing delimiter collision in large MBOX files where body text contains lines beginning with From.
  • Optimizing heap memory usage when converting massive 50GB–100GB mailboxes.

Accomplishments that I'm proud of

  • Zero external mail client dependency: 100% standalone execution.
  • Streaming throughput reaching 25–27 GB per hour with zero RAM exhaustion.
  • Full support for 17 export formats covering desktop archives, databases, and enterprise cloud APIs.

What I learned

Deep forensic reconstruction of legacy email databases and modern cloud authentication protocols (OAuth 2.0 PKCE and Google Service Account P12 authorization).

What's next for Prism Migration Suite — PST & MBOX 2026 Engine

Expanding enterprise super-admin batch tenant-to-tenant migration pipelines and automated scheduled backup CLI daemons.

Built With

  • apple-silicon
  • b-tree
  • java
  • mime-rfc822
  • oauth
  • windows-11
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