Inside the app
A closer look.






About this app
Made for a clear purpose.
Mailfossil: Archive Lab is a focused, fully on-device app. An offline MBOX and EML archive explorer for MIME structure, attachments, threads, dates, participants, duplicates, search, redaction planning, and evidence export.
KEY FEATURES - Stream large MBOX files without uploading messages - Inspect MIME trees, encodings, attachments, and headers - Reconstruct threads and participant timelines - Find exact and near-duplicate messages - Export selected metadata or redaction worksheets - Complete bundled sample and local comparison workflow - Local PDF report and Apple system share export - Original offline technical reference library
ONE-TIME AND PRIVATE - One paid download; no subscription or in-app purchase - No account, advertising, analytics, tracking, or developer-operated backend - Core features and bundled content work offline - Work remains on device unless you deliberately share or export it through an Apple system interface
Archive inspection aid. Headers can be forged and threading is heuristic; preserve originals and follow legal, privacy, retention, and evidentiary requirements.