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Email File Viewer

Instantly open and read .eml, .msg, and .mbox files. Processing happens entirely in your browser—your sensitive emails are never uploaded to our servers.

Drag & Drop an email file here

Supports .eml, .msg, and .mbox files

Why use a Client-Side Email Reader?

Email files like .eml and .msg often contain highly sensitive personal, legal, or corporate information. Using a traditional online converter forces you to upload these private documents to a remote server, creating a massive security risk.

This Rapid Calc tool utilizes modern HTML5 APIs to parse Microsoft Outlook and standardized MIME files directly inside your computer's RAM. Disconnecting from the internet while reading your files will prove they are never transmitted anywhere.

Supported Formats

  • .EML (Electronic Mail): The universal standard for saved emails, commonly exported from Gmail, Apple Mail, and Thunderbird.
  • .MSG (Outlook Message): Microsoft's proprietary binary format used when dragging an email out of the Outlook desktop app.
  • .MBOX (Mailbox): An archive format containing multiple EML files stacked together, commonly generated by Google Takeout.

Note: PST and OST files are massive database archives (often containing gigabytes of data). Web browsers cannot safely open database files of that size without crashing, so dedicated desktop software is required for those specific formats.