MBOX explained

An MBOX is many internet messages in one long file.

Messages are separated by From_ lines and contain normal email headers and MIME bodies. Real archives vary, so tolerant incremental parsing matters.

Free · private · no uploads · no account

Open an email file

Drop it here or choose it from your computer.

MSGEMLEMLXWINMAIL.DATMBOX

Processed locally. Your file never leaves this browser.

How it works

Three steps. No detour through a server.

  1. 1Drop the archive
  2. 2Index message boundaries progressively
  3. 3Search and open individual messages

Common in Unix mailboxes and Google Takeout

May grow to many gigabytes

The source archive remains read-only

Straight answers

Common questions

Why not open MBOX in a text editor?

You can, but attachments are encoded and message boundaries, MIME structure, and character sets make large archives hard to navigate manually.

Does MBOX contain folders?

A single MBOX is usually one flat message sequence. Some exports use multiple MBOX files to represent folders or labels.