How to Export Emails from Proton Mail (Full Mailbox Backup)

If you want to know how to export emails from Proton Mail — for a backup, for a lawyer, for a migration, or just because you like owning your own archive — Proton ships two supported paths and no third one worth using. The Proton Mail Export Tool downloads every message as decrypted EML plus a JSON metadata file. Proton Mail Bridge, available on paid plans, turns your Proton account into a local IMAP server that Thunderbird, Apple Mail, or Outlook can talk to like any other mailbox.

This guide walks both paths, notes what does not survive the trip, and shows how to run the export without disrupting the inbox you use every day. It is written as a portability and backup guide, not a persuasion piece to leave Proton. If Proton is working for you, back up the archive and stay.

What actually moves — and what doesn't#

The first thing to get straight is what an export from an end-to-end encrypted mailbox even means. Proton stores your mail encrypted with keys derived from your password, and no export format can carry that encryption into a foreign client. Both the Export Tool and Bridge decrypt on your device before writing anything out. What lands on your disk is readable mail, and that is deliberate — a locked archive you cannot open on a fresh laptop is not a backup.

So plan around that fact rather than fight it. What comes out cleanly:

• Every message body, decrypted, in EML — the plain email format Thunderbird, Outlook, and Apple Mail all read.
• Attachments, embedded and preserved inside the EML files.
• Standard headers: From, To, Cc, Bcc, Subject, Date, Message-ID, References, In-Reply-To.
• Folder structure — the Export Tool mirrors your Proton labels and folders into a directory tree.
• A JSON sidecar per message with Proton-side metadata (labels, flags, timestamps) for anyone rebuilding an archive.

What does not move, or moves with an asterisk:

• End-to-end encryption at rest. The exported files are readable. Encrypt the export folder yourself if that matters — full-disk encryption, a VeraCrypt container, or a signed archive.
• Encrypted messages you received from outside Proton using a password. These are decrypted at export time using the key on your account; a foreign client will see the plaintext.
• Proton-specific features: self-destructing messages that have already expired, sieve filters, and any label colours are not part of the EML spec and will not appear in another client.
• Contacts and calendar. The Export Tool exports mail. Contacts export separately from the Proton web app (vCard), and Proton Calendar exports as ICS from Proton Calendar's own settings.

Pre-migration checklist#

Ten minutes of preparation saves an evening of re-runs. Work through this list before you start.

• Know your Proton plan. The Export Tool is available on every plan, free included. Bridge requires a paid plan that includes Proton Mail (Mail Plus, Proton Unlimited, or a Business tier).
• Have your mailbox password ready. It is the one that decrypts your messages, not your two-factor code. If you use single-password mode it is the same as your login password.
• Check disk space. A mailbox of 10,000 messages with attachments typically lands at 3–8 GB on disk once decrypted. Free up double that so the tool has room to work.
• Turn off any background sync you have on the same account. Bridge and the Export Tool both authenticate as your account; running Bridge and the Export Tool simultaneously is fine, but stop any third-party sync jobs you set up earlier so the audit trail is clean.
• Pick a destination folder outside your Documents cloud-sync path. You do not want a half-finished export uploading to iCloud while it is being written.
• If you have two-factor on, keep your authenticator open. Both tools prompt for a TOTP code at sign-in and will retry a few times before locking out.

Method 1 — the Proton Mail Export Tool (EML + JSON to disk)#

The Export Tool is the right choice for a one-off backup or a migration snapshot. It downloads once, writes to your disk, and stops. It runs on Windows 10 or later, macOS 10.15+ (Intel or Apple Silicon), and Ubuntu 20.04 LTS. It is free.

1. 1

   Download the tool from Proton

   Sign in to proton.me, open the Export Tool page in Proton Support, and grab the installer for your OS. Do not pull a build from a third-party mirror; the tool decrypts your mail on your device and you want the signed release from Proton.

2. 2

   Install and launch

   Install like any regular application. On macOS you may need to allow it in System Settings → Privacy & Security the first time; on Ubuntu, mark the AppImage executable if it did not download that way.

3. 3

   Sign in with your Proton credentials

   Enter your Proton email and password, then your 2FA code if enabled. The tool authenticates against your account and prepares to fetch. If you have two-password mode, it will also prompt for the mailbox password.

4. 4

   Choose the export folder

   Point the tool at a folder on a disk with double the space you think you need. Local drive, not a network share, and not a consumer cloud-sync folder. The tool will create a subdirectory tree mirroring your Proton labels.

5. 5

   Select what to export

   By default the tool exports all folders and labels. You can narrow the selection to a date range or specific labels if you are only backing up a project or a year. For a full mailbox backup, leave everything selected.

6. 6

   Run the export and leave it alone

   The tool decrypts and writes messages one by one. For 10,000+ messages, expect at least half an hour, and much longer on a slow connection. If the tool is interrupted, it can resume from where it stopped rather than re-downloading everything.

Method 2 — Proton Mail Bridge into a local client#

Bridge is the right choice when you want the archive to stay live. It runs as a small background app on your Mac, Windows, or Linux machine, creates a local IMAP + SMTP server on 127.0.0.1, and hands out an application password your desktop client uses to log in. To the client it looks like an ordinary IMAP account; underneath, Bridge decrypts on the way in and encrypts on the way out. Bridge requires a paid Proton plan.

The end result is that a mail client like Thunderbird can download every message to a local profile, keep syncing new mail as it arrives, and stay usable offline. It is a live mirror rather than a snapshot.

1. 1

   Install Proton Mail Bridge

   Download Bridge from proton.me/mail/bridge for your OS and install it. Sign in with your Proton account and complete 2FA. Bridge will do an initial sync in the background — this can take a while on a big mailbox.

2. 2

   Copy the Bridge-generated password

   In Bridge, open your account and reveal the IMAP + SMTP settings. Bridge shows a unique password that is not your Proton login password. Copy it. This password only works against the local Bridge server on your machine.

3. 3

   Add the account in Thunderbird, Apple Mail, or Outlook

   Create a new IMAP account. Server = 127.0.0.1, port and security exactly as Bridge lists (typically STARTTLS on 1143 for IMAP and STARTTLS on 1025 for SMTP), username = your Proton address, password = the Bridge-generated one. Do not use your Proton password here.

4. 4

   Let the client download everything

   Set the account to sync all folders, not just the inbox. In Thunderbird: right-click the account → Subscribe → tick every folder. Then leave the client running so it can finish the initial download. The mail now lives in the client's local profile and works offline.

5. 5

   Back up the client profile if you want a true archive

   Once the download is complete, back up the client's mail profile folder (Thunderbird's profile, Apple Mail's ~/Library/Mail, Outlook's PST/OST). That folder is your portable archive going forward.

What breaks in the export — compatibility table#

Both paths preserve the important things and lose a handful of Proton-specific ones. The table below is the practical version of that trade — check the column for the tool you are using before you commit to it.

How to roll back if something goes wrong#

The reassuring thing about both paths: neither one changes anything inside your Proton account. The Export Tool only reads, and Bridge only proxies. There is no destructive step to undo. Rollback is really about clean-up rather than repair.

• If the Export Tool failed partway through, delete the incomplete export folder and re-run — the tool starts fresh from the top and produces a clean tree. Do not merge two half-runs by hand; the JSON sidecars can drift.
• If Bridge got stuck in the initial sync, quit Bridge, delete the local Bridge cache (Bridge's Settings → Help → Advanced settings for the exact path on your OS), sign in again, and let it resync. Your Proton mailbox is untouched.
• If the desktop client wrote wrong-looking data into its local profile (duplicate messages, missing folders), remove the account from the client rather than the mail folder, then re-add it with the Bridge credentials. IMAP will re-download the correct state.
• If you exported to a synced cloud folder by accident, delete the export from both local and cloud, empty the cloud trash, and re-run to a local-only path. Assume anything that briefly hit the cloud is out of your hands.

Doing it without downtime#

For a working mailbox — one you still need to send and receive from while the export runs — the goal is that no message goes missing during the switch and no reply lands in a mailbox you have already stopped watching. The pattern below has held up for most Proton migrations.

1. 1

   Run the export against a stable snapshot

   Pick a low-traffic window (Sunday evening works). Kick off the Export Tool then. Anything that arrives after it starts will not be in this archive — that is fine, you will pick up the gap in step 3.

2. 2

   Keep Proton as your live inbox during the transition

   Do not change your MX records or forwarding yet. Continue sending and receiving from Proton normally. The export is a backup, not a cutover.

3. 3

   Set up Bridge in parallel for the gap

   Once the one-shot export finishes, install Bridge and point a desktop client at it. From this point on, every new message hits both Proton's web app and your local client. There is no window where mail is only in one place.

4. 4

   Cut over only after two clean days on the local client

   Give the local client 48 hours of live traffic. If threading, attachments, and sent-mail all behave, you can decide whether to keep Proton and just retain the backup, or switch primary reading to the local client, or migrate to a different provider using the archive as the source.

5. 5

   Update forwarding and 2FA references last

   If you are moving off Proton entirely, only touch account recovery emails, 2FA seeds tied to your Proton address, and MX/forwarding rules after the local archive has proven itself. Every one of those changes is a place a lost email hurts you later.

If you're moving on from Proton after the export#

This is the section where we should say plainly what we build, and where the honest answer changes depending on what you do next. We build AI Emaily, an AI-native email client that puts an approve-before-send agent on your Gmail, Outlook, Fastmail, or IMAP inbox. If you are staying in Proton, we are not the tool for you — AI Emaily runs as a hosted service, and Proton Bridge exposes IMAP only on your local machine (127.0.0.1), which our servers cannot reach. Thunderbird, Apple Mail, or Outlook through Bridge is the right pairing for staying on Proton.

If the export is the first step of a move to Gmail, Outlook, Fastmail, or any IMAP host, that is where we fit. Point the exported EML at the new provider (their web importer, or a re-upload from Thunderbird's IMAP account), then connect the new inbox to AI Emaily so the archive lands somewhere with triage, drafts in your voice, and a full audit trail on every automated action. See how much it costs on our pricing page — there is a free trial, and no free tier.

Wrap-up#

You have two Proton-supported paths and they answer different questions. The Export Tool answers "give me a copy of everything I can put on a drive." Bridge answers "let me keep working in a normal desktop client from now on." Most people who are serious about their archive run both once: the tool for the offline backup, Bridge to keep the working mailbox alive.

Whichever you pick, the mail comes out decrypted, the folder structure survives, and Proton-specific extras like sieve rules and self-destruct timers do not. Plan for that up front, verify the archive opens before you prune anything on the server, and treat the exported files like the sensitive material they now are.