Your mail stays on your device.

The converter is designed around local file processing.

Email files and conversion

Your selected files are read by code running in your browser. Email contents, attachment payloads, filenames, and generated spreadsheets are not uploaded by the converter. The converter does not send your messages to an AI service or request access to your mailbox account.

What stays in memory

During conversion, the app holds the current message, up to 100 preview records, and the generated output. Standard mode holds output in browser memory. Large-file mode writes the main CSV to a file you choose; an optional attachment manifest is still prepared in memory.

Start over releases the app's references to the preview and output, and closing the tab ends its session. The browser controls when released memory is reclaimed. The app does not save email data in browser databases or local storage.

Downloads

Downloaded CSV and ZIP files remain on your device until you remove them. Large-file mode writes to the location you authorize. The optional source_file column and attachment manifest can include your selected filenames.

Website access

Loading this website makes ordinary requests to its hosting service. That service can process information such as IP address, request time, and browser information to deliver and protect the site. Site access may use sign-in cookies under the hosting provider's policies.

The converter itself includes no advertising scripts, analytics trackers, third-party fonts, or conversion telemetry. Links to Google, Apple, or Thunderbird open their own websites, which have separate policies.

Scope of this policy

This policy describes this version of MBOX-CSV. It does not describe an older server-based converter or any other website that may use a similar name.

Updated October 15, 2026