You downloaded Google Takeout — now what?

By Michael, founder of EmailAttic · September 2026 · 7 min read

You did the responsible thing: exported your Gmail with Google Takeout. Now there's a mysterious multi-gigabyte zip on your desktop, and inside it a file type you've never seen. Here's what you're holding and what to do with it.

What's actually in the zip

Unzip it and look for a Takeout folder. If you exported Mail, the important file is inside Takeout/Mail/:

• All mail Including Spam and Trash.mbox — this single file is your entire mailbox: every message, every attachment, all in one container. It can be tens of gigabytes.
• Possibly additional .mbox files for individual labels, if you chose to export by label.
• If you selected other products: Contacts (as .vcf/.csv), Calendar (as .ics), Drive, Google Photos, and so on, each in its own folder.

Big exports arrive as multiple numbered zips (takeout-...-001.zip, -002.zip…). You need all of them — each contains a different slice, and mail can span several. Download every part before the links expire (they only last about a week), and keep the zips until you've verified the contents.

What an MBOX file is

MBOX is one of the oldest email formats there is — a plain text file with every message concatenated one after another, attachments encoded inline. That age is a feature: it's readable by software from every decade, and it will still be readable in thirty years. The downside: it's one giant opaque lump. You can't browse it in Explorer, search it, or open message #40,000 without a tool that understands it.

How to actually open it

The standard free route is Thunderbird (Windows/Mac/Linux) with the ImportExportTools NG add-on: install both, then import the .mbox file and browse your archive like a mailbox. It works, with two caveats from experience: very large MBOX files import slowly, and you're now depending on an app's internal storage rather than plain files.

From "a file I downloaded" to "an archive that lasts"

A Takeout zip in your Downloads folder isn't preservation — it's procrastination with better packaging. To make it permanent:

1. Get it out of Downloads. Copy the zips to two places — an external drive and the computer, minimum.
2. Convert to individual files. Splitting the MBOX into one .eml file per message turns the opaque lump into ordinary files you can browse, search, and back up incrementally.
3. De-duplicate. Gmail's "All Mail" includes everything, and if you also have older exports or PST backups from the Outlook years, the overlap is massive. When I merged my family's sources, half of all messages were duplicates.
4. Organize by person and account, not by which export it came from.
5. Re-export yearly. Takeout is a snapshot, not a sync. A calendar reminder once a year keeps the archive current.