How to Export Gmail to Thunderbird (Step by Step)

Backup & migration

Gmail Exporter Guide

Two very different goals, two methods

People say "export Gmail to Thunderbird" to mean one of two things, and it helps to know which you want before you start. The first goal is to use Gmail from Thunderbird — read, send and organise mail in a desktop app instead of the web. The second is to archive Gmail into Thunderbird — pull your messages into a permanent local store you keep regardless of what happens to the account. The first is best served by IMAP, the second by an MBOX import. We will walk through both so you can pick, or do both.

Method 1 — Connect Gmail with IMAP (live mailbox)

IMAP makes Thunderbird a window onto your live Gmail. Messages stay on Google's servers and Thunderbird mirrors them, so anything you do in one place shows up in the other. This is the right method if you simply want a desktop client.

1. Turn on IMAP in Gmail. In Gmail's Settings under "Forwarding and POP/IMAP", enable IMAP access.
2. Add the account in Thunderbird. Choose Account Settings → Add Mail Account, enter your address, and let Thunderbird auto-detect the Gmail servers.
3. Sign in with Google. Thunderbird uses Google's secure sign-in (OAuth); approve it and, if you use two-step verification, complete the prompt.
4. Let it sync. Thunderbird downloads your folders and messages. To keep an offline copy, enable "Keep messages in all folders for this account on this computer" in the synchronisation settings.

Your Gmail labels appear as folders. One quirk: because a Gmail message can carry several labels, it may show in several folders, and the special "All Mail" view behaves differently from a normal folder. That is normal IMAP behaviour, not an error.

Method 2 — Import an MBOX archive (permanent copy)

IMAP has a weakness for archiving: if the account is closed, suspended or loses access, the mail in Thunderbird can disappear with it, because IMAP is a mirror, not a copy. For a genuine archive you want your mail as an MBOX file — a single self-contained store that Thunderbird can import and that you own outright. This is the method to choose when the point is preservation.

First, create the MBOX. A local exporter such as Gmail Exporter builds the file on your own machine, so your mail is never sent to anyone else's server.

1. Filter what you want to archive. A label, a date range, or your whole mailbox — narrow it with a Gmail search first if you like.
2. Export to MBOX with the local tool. The file saves to your Downloads.
3. Import into Thunderbird. Install the free ImportExportTools NG add-on, right-click a local folder, choose Import → Import mbox file, and select your export. Every message loads into that folder.

Which method should you choose?

Many people do both: IMAP for everyday reading and a periodic MBOX export for safekeeping. If you are leaving a company, the MBOX route is the one that matters — see saving Gmail before leaving a job.

Making sure attachments come across

Both methods preserve attachments. Over IMAP, Thunderbird downloads each attachment with its message once syncing completes. In an MBOX file, attachments are encoded inside the file itself, so importing brings them along automatically. If your real aim is to pull the files out as documents rather than keep them inside emails, that is a separate job — our guide to downloading all Gmail attachments covers extracting them into folders.

What happens to labels and folders

Gmail's labels are not quite the same thing as folders, and the mismatch is the source of most surprises. Over IMAP, each label becomes a folder, but a message with three labels appears in three folders — it is one message shown in several places, not three copies. In an MBOX export, the structure depends on how you exported; exporting per label keeps things tidy. If some labels seem to vanish when you move mail around, our explainer on why labels go missing in Takeout applies to Thunderbird imports too and explains the underlying reason.

Reading and searching your archive later

Once imported, an MBOX archive behaves like any Thunderbird folder: full-text search, sorting, and offline access all work, with no Gmail connection required. If you ever want to read the MBOX outside Thunderbird — on a machine without it installed — our guide to opening an MBOX file lists other viewers. The advantage of the file format is exactly this portability: your archive is not locked to one app.

A sensible backup routine

Thunderbird plus a periodic MBOX export makes a solid personal backup strategy. Use IMAP for daily mail, and every few months export a fresh MBOX and store it on an external drive or in cloud storage. That gives you a live mailbox and a series of dated, self-contained snapshots you fully control. It is the same thinking behind a proper Gmail inbox backup: never let your only copy of important correspondence live solely on someone else's servers.

Migrating between accounts through Thunderbird

Thunderbird doubles as a bridge when you are moving mail from one Gmail account to another, or from Gmail to a different provider entirely. Connect both accounts over IMAP, and you can drag messages or whole folders from one to the other and Thunderbird handles the transfer. For a one-time move this is often simpler than any dedicated migration tool, and it keeps you in control of exactly what goes across.

If the destination is not ready yet — a new account you have not set up, or a provider you have not chosen — the MBOX route is the safer interim step: export now, import into Thunderbird as a holding archive, and forward it into the new account later. Our guide to migrating Gmail to another account covers the account-to-account options in full, and Thunderbird fits neatly alongside them as the desktop workhorse for the job.

The bottom line

To use Gmail in Thunderbird day to day, connect the account with IMAP for a live, synced mailbox. To preserve your mail permanently, export it to an MBOX file with a local tool and import it through the ImportExportTools NG add-on for a portable archive you own. Both keep your attachments; the MBOX route also survives the account being closed. Pick by your goal — or do both — and your Gmail is safely in Thunderbird either way.