ProtonMail IMAP SMTP Setup Guide

Complete configuration guide for ProtonMail Bridge to enable IMAP and SMTP access in any email client with end-to-end encryption

ProtonMail Bridge Settings

IMAP Settings (Incoming Mail)

Server:127.0.0.1
Port:1143
Security:STARTTLS

SMTP Settings (Outgoing Mail)

Server:127.0.0.1
Port:1025
Security:STARTTLS

Before You Start

ProtonMail Bridge Required

ProtonMail requires the Bridge application to enable IMAP/SMTP access while maintaining end-to-end encryption.

  • Ensure you have a ProtonMail account (paid subscription required for Bridge)
  • Download and install ProtonMail Bridge application
  • Have your email client ready for configuration
  • Bridge works on Windows, macOS, and Linux

Step 1: Download and Install ProtonMail Bridge

  1. Go to ProtonMail Bridge download page
  2. Download the appropriate version for your operating system:
    • Windows: .exe installer
    • macOS: .dmg package
    • Linux: .deb or .rpm package
  3. Install the Bridge application following the setup wizard
  4. Launch ProtonMail Bridge after installation

Step 2: Configure ProtonMail Bridge

  1. Open ProtonMail Bridge application
  2. Click "Add account" or the "+" button
  3. Enter your ProtonMail credentials:
    • Email address: your ProtonMail address
    • Password: your ProtonMail password
    • Two-factor authentication code (if enabled)
  4. Wait for Bridge to sync your account
  5. Note the generated Bridge password (different from your ProtonMail password)
  6. Keep Bridge running in the background

Important Note

Bridge generates a unique password for email client access. Use this Bridge password, not your ProtonMail password.

Step 3: Configure Your Email Client

Microsoft Outlook Configuration

  1. Open Outlook and go to File → Add Account
  2. Choose "Manual setup or additional server types"
  3. Select "POP or IMAP"
  4. Enter your account information:
    • Your Name: [Your full name]
    • Email Address: [your-email@protonmail.com]
    • Account Type: IMAP
    • Incoming mail server: 127.0.0.1
    • Outgoing mail server: 127.0.0.1
    • User Name: [your ProtonMail address]
    • Password: [Bridge generated password]
  5. Click "More Settings" → "Advanced" tab
  6. Set incoming server port to 1143 with STARTTLS
  7. Set outgoing server port to 1025 with STARTTLS
  8. Check "My outgoing server requires authentication"

Mozilla Thunderbird Configuration

  1. Open Thunderbird and go to File → New → Existing Mail Account
  2. Enter your name, ProtonMail address, and Bridge password
  3. Click "Configure manually"
  4. Set the following settings:
    • Incoming: IMAP, 127.0.0.1, Port 1143, STARTTLS
    • Outgoing: SMTP, 127.0.0.1, Port 1025, STARTTLS
    • Username: your ProtonMail address
    • Authentication: Normal password
  5. Click "Re-test" and then "Create Account"

Apple Mail Configuration

  1. Open Mail app and go to Mail → Preferences → Accounts
  2. Click the "+" button to add a new account
  3. Select "Other Mail Account"
  4. Enter your name, ProtonMail address, and Bridge password
  5. Configure manually:
    • Incoming Mail Server: 127.0.0.1
    • Outgoing Mail Server: 127.0.0.1
    • Use STARTTLS for both incoming and outgoing
    • Incoming port: 1143, Outgoing port: 1025
  6. Click "Sign In" to complete the setup

Bridge Management

Important Bridge Information

  • Bridge must be running for email clients to work
  • Bridge automatically starts with your computer
  • You can manage multiple ProtonMail accounts
  • Bridge maintains end-to-end encryption

Troubleshooting Common Issues

Bridge Not Connecting

  • Ensure Bridge application is running
  • Check your ProtonMail subscription (Bridge requires paid plan)
  • Restart Bridge application
  • Check firewall settings for Bridge

Authentication Failed

  • Use Bridge generated password, not ProtonMail password
  • Regenerate Bridge password in Bridge settings
  • Ensure two-factor authentication is properly configured
  • Check that account is properly added to Bridge

Connection Issues

  • Verify localhost (127.0.0.1) connections are allowed
  • Check that ports 1143 and 1025 are not blocked
  • Disable antivirus email scanning temporarily
  • Try restarting both Bridge and email client

Security Features

  • End-to-end encryption maintained through Bridge
  • Zero-access encryption for maximum privacy
  • Local decryption on your device only
  • Swiss privacy laws protection
  • Open source Bridge application

Frequently Asked Questions

Do I need a paid ProtonMail account for Bridge?

Yes, ProtonMail Bridge is only available for paid subscribers (Plus, Professional, or Visionary plans).

Can I use Bridge on multiple devices?

Yes, you can install and use Bridge on multiple devices with the same ProtonMail account.

Is my email still encrypted when using Bridge?

Yes, Bridge maintains ProtonMail's end-to-end encryption. Emails are decrypted locally on your device.

What happens if Bridge stops working?

Your email clients won't be able to connect. Restart Bridge or use ProtonMail's web interface as a backup.