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Mail Archive Viewer Support

Need help with the app? Learn more about the app or browse our support documentation below.

About the App

Mail Archive Viewer is a native macOS application for opening and reading email archive files. It supports PST, OST, OLM, MBOX, and EML formats — no Outlook or other email client required.

Getting Started

  1. Download Mail Archive Viewer from the Mac App Store
  2. Launch the app
  3. Open an archive file using File → Open Archive (⌘O) or drag and drop a file onto the window
  4. Browse folders in the left sidebar
  5. Click a message to read it

Supported File Formats

  • PST — Outlook for Windows Personal Storage Table
  • OST — Outlook Offline Storage Table
  • OLM — Outlook for Mac Archive
  • MBOX — Apple Mail, Thunderbird, Gmail exports (including Apple Mail directory-style .mbox packages)
  • EML — Individual email message files

Features

Opening Archives

  • ⌘O: Open an archive file
  • Drag & Drop: Drag archive files directly onto the app window
  • Multiple archives: Open several archives simultaneously and switch between them in the sidebar

Browsing Emails

  • Folder tree: Navigate the archive's folder structure in the left sidebar
  • Message list: Browse emails in the middle column
  • Email preview: Read the full email with headers, body, and attachments in the right column
  • Search: Type in the search bar to find messages by sender, recipient, or subject
  • Sort: Click the sort icon (↑↓) in the message list to sort by date, sender, or subject

Saving & Exporting

  • Export as EML: Click the "Export as EML" button to save any message as a standard .eml file
  • Save attachments: Click any attachment chip to save it to disk

Closing Archives

  • ⌘W: Close the currently selected archive
  • Hover + ×: Hover over an archive name in the sidebar and click the × button

Frequently Asked Questions

Q: Why can't I open my PST file?

A: If you get a "Failed to parse archive" error, the PST file may be encrypted or password-protected. Mail Archive Viewer supports standard PST files but cannot open encrypted archives. Also ensure the file is not corrupted — try opening it in another tool to verify.

Q: My MBOX file doesn't appear in the open dialog

A: Apple Mail exports .mbox as a directory package. Make sure "canChooseDirectories" is enabled — the app supports both file-style and directory-style MBOX archives. If the file still doesn't appear, ensure it has the correct .mbox extension.

Q: Some emails show no content

A: This can happen with emails that use unusual encodings or MIME structures. The app handles most standard email formats, but extremely non-standard messages may not render correctly.

Q: Are remote images in emails blocked?

A: Yes, by design. Remote images (including tracking pixels) are blocked to protect your privacy. JavaScript is also disabled in email previews. This is a security feature and cannot be disabled.

Q: Can I edit or delete emails in an archive?

A: No. Mail Archive Viewer is a read-only viewer. It cannot modify archive files. You can export individual messages as EML files and save attachments.

Q: What macOS version is required?

A: macOS 14.0 (Sonoma) or later.

Keyboard Shortcuts

  • ⌘O: Open archive file
  • ⌘W: Close current archive
  • ⌘F: Focus search field

Troubleshooting

Large archive takes a long time to open

Archives with thousands of messages need to be fully parsed on first open. A loading indicator will appear. For very large PST files (1GB+), this may take a minute.

App crashes on open

If the app crashes when opening a specific file, the archive may be corrupted. Try a different file to confirm the app works normally, then contact support with details about the problematic file.

Support Contact

For support inquiries, please contact us via our contact form or email [email protected].

Version Information

Current Version: 1.0.0

Requires: macOS 14.0 (Sonoma) or later