July 2026 Update. The Hide My Email flaw is leaking Apple aliases (publicly disclosed on July 1st, still not fixed). Another argument for sovereign aliases: see the email comparison update.

May 2026 Update. If you’re using Proton Bridge with Apple Mail, keep Bridge up to date: Proton has enabled post-quantum encryption on the Mail side (manual activation required). Bridge supports it transparently, but a recent version is needed for newly encrypted emails to be readable on the Apple Mail side. Details in the radar.

Proton Mail encrypts your emails structurally, open-source, mathematical, verifiable. You can use it directly via its native app, free on Mac, iOS, and Android. It gets the job done.

But if you want to stay in Apple Mail, with Spotlight, your filtering rules, your keyboard shortcuts, your macOS notifications, you need Proton Bridge. In 10 minutes, you’ll connect Proton Mail to Apple Mail via Bridge. No more web app. Everything in Mail.app, end-to-end encrypted.

You’ll need a Mac on macOS Tahoe, Sequoia, or Sonoma, a Proton Mail Plus (or higher) account, and 10 minutes. At the end, Apple Mail will display your Proton emails natively, with zero-knowledge encryption running underneath.

Read: Why your mail client is a sieve

Before you start

What you’ll need:

• A Mac on macOS Tahoe (26.x), Sequoia (15.x), or Sonoma (14.x)
• A Proton Mail Plus (or higher) account. The free plan doesn’t include Bridge.
• Apple Mail installed (pre-installed on macOS)
• 10 minutes

What will change:

• Your Proton emails will appear in Apple Mail, with Spotlight, keyboard shortcuts, macOS notifications
• E2EE encryption is maintained: keys never leave your Mac
• Pixel spies and remote resources are filtered by Proton before reaching Apple Mail

What won’t change:

• Emails sent to non-Proton addresses (Gmail, Outlook) aren’t E2EE encrypted on the recipient’s side
• Bridge uses 150-300MB of RAM in the background
• No instant push: Apple Mail polls Bridge (~1 minute)

Warning: If Bridge is closed or crashes, Apple Mail won’t receive anything until it’s relaunched. Make sure Bridge is in your macOS login items and its icon is visible in your active apps menu, top right of your screen.

On the pixel spy protection front, the Proton + Apple Mail combo plays on two fronts. Proton filters tracking pixels on the server side, before emails even reach Bridge. Apple Mail, with “Protect Mail Activity” (Mail Privacy Protection), masks your IP and proxies images via Apple servers for the rest. The CNIL recommendation from April 14, 2026 on tracking pixels makes this double protection enforceable starting mid-July 2026. You don’t need to configure anything extra, both are active by default.

Read: Why your mail client is a sieve, including the CNIL chapter

Steps

Step 1: Download Proton Bridge

Go to proton.me/mail/bridge and download the macOS version. It’s a standard .dmg.

What you should see: a .dmg file in your Downloads folder.

Step 2: Install Bridge

Open the .dmg, drag Bridge into /Applications, launch it. A Proton icon appears in the menu bar.

Important: Allow Bridge to add itself to your macOS login items when prompted. Without this, Bridge won’t start automatically with your session, and Apple Mail will stay silent after each restart.

What you should see: the Proton Bridge icon in your menu bar.

Step 3: Connect to Bridge

Click on the Bridge icon in the menu bar > open the main interface > Connect > enter your Proton Mail credentials > validate the 2FA if you have it enabled (recommended).

Bridge starts synchronizing your emails in the background. Give it a few minutes if your mailbox is large.

What you should see: your account displayed in the Bridge interface, synchronization in progress.

Step 4: Retrieve IMAP credentials

In the Bridge interface: click on your account > Messaging Settings section. Bridge generates a specific password for Apple Mail, different from your Proton password. Copy it.

Also note:

• Incoming server: 127.0.0.1, port 1143
• Outgoing server: 127.0.0.1, port 1025

What you should see: the IMAP/SMTP settings displayed with a generated password.

Step 5: Add the account in Apple Mail

Open Apple Mail > Mail (menu) > Add Account > Other Mail Account (not iCloud, not Exchange, the generic option at the bottom).

Fill in:

• Full Name: your name
• Email Address: your @proton.me address (or Proton alias)
• Password: the Bridge password you just copied (not your Proton password)

Apple Mail will try to connect automatically, it will probably fail. That’s normal. Click Next to access manual configuration.

Incoming Mail Server:

• Server: 127.0.0.1, Port: 1143, SSL/TLS: disabled, Authentication: normal password

Outgoing Mail Server:

• Server: 127.0.0.1, Port: 1025, SSL/TLS: disabled, Authentication: normal password

What you should see: your Proton account appears in the sidebar of Apple Mail.

Why SSL disabled? The connection between Apple Mail and Bridge only goes through 127.0.0.1, your own machine, never the network. Bridge handles TLS encryption with Proton servers itself. Enabling SSL on top would create a certificate conflict.

Step 6: Check synchronization

Once the account is added, Apple Mail starts downloading your emails via Bridge. Depending on the volume, this can take a few minutes to a few hours. The Bridge icon in the menu bar shows the progress.

Check three things:

1. IMAP folders are imported. Your inbox, custom folders, Sent, Trash, Spam should all appear in the sidebar of Apple Mail under your Proton account. If a folder is missing, force a resync: right-click on the account > Synchronize.

2. Your identities are configured for replying. If you have multiple Proton addresses (aliases, custom domain), check that you can reply from each. Go to Mail > Preferences > Accounts > [your Proton account] > Email Addresses: all your Proton addresses should be listed. When writing an email, the “From:” field offers the choice. If an address is missing, Bridge should sync it normally, relaunch Bridge if necessary.

3. Test email. Send a test email from another account to your Proton address. If it arrives in Apple Mail, you’re good. Reply to it from Apple Mail to check sending works too.

What you should see: your Proton emails in Apple Mail, all folders visible, all your identities available in the “From:” field, test email received and reply sent.

If it’s not working

Problem: Bridge won’t start / doesn’t appear in the menu bar

Probable cause: Bridge isn’t in the login items.
Solution: System Preferences > General > Open (or Login Items depending on your macOS version). Check that Bridge is listed and enabled. If it’s not, launch it manually from /Applications.

Problem: Emails aren’t sending (SMTP error)

Probable cause: SMTP credentials in Apple Mail are incorrect.
Solution: Mail > Preferences > Accounts > [your Proton account] > Outgoing Mail Server Settings. Check that the server is 127.0.0.1 port 1025, the password is the Bridge one (not the Proton one), and SSL is disabled. If Apple Mail “auto-corrected” the port or enabled SSL during setup, that’s likely where the issue is.

Problem: Sync is slow, emails take too long to arrive

Probable cause: polling frequency is too low.
Solution: Mail > Preferences > Accounts > [your account] > Check for New Messages. Change it to “Every 30 seconds” if your Mac is always plugged in. Note that this slightly increases CPU usage.

Problem: Bridge asks for re-authentication after update

Probable cause: Proton updated Bridge, old credentials are invalid.
Solution: in Bridge, reconnect. New IMAP credentials are generated automatically. Update the password in Apple Mail (account preferences, SMTP section). You don’t need to reconfigure everything, just the password.

Problem: “Can’t connect” at startup

Probable cause: Apple Mail started before Bridge was ready.
Solution: wait a few seconds, then Mailbox > Get All New Messages. Bridge needs a few seconds to start up.

For the impatient

This article connects Proton Mail to Apple Mail via Proton Bridge in 10 minutes. You keep the native macOS interface with Proton’s E2EE encryption underneath. Requirements: Proton Mail Plus account.

In short:

1. Download Bridge from proton.me/mail/bridge
2. Install, launch, allow in macOS login items
3. Connect with Proton credentials
4. Copy the Bridge-generated password (not your Proton password)
5. Apple Mail > Add Account > Other Mail Account
6. IMAP server: 127.0.0.1 port 1143, SSL disabled
7. SMTP server: 127.0.0.1 port 1025, SSL disabled
8. Password: Bridge-generated one
9. Send a test email to check

Try Proton Mail Plus, starting at €3.99/month