Proton Mail IMAP and SMTP settings

The server names, ports and sign-in details you need to add Proton Mail to Outlook, Apple Mail, Thunderbird or any other email app.

By David Ray · Updated October 17, 2026 · How we research

Proton Mail server settings

Username and password

Username: Your Proton address, as shown in Proton Mail Bridge.

Password: Use the password that Proton Mail Bridge shows you, not your Proton password.

Good to know

• Proton encrypts your mail, so standard email apps can't connect to it directly. Proton Mail Bridge is a small program that runs on your computer and translates between your app and Proton.
• Bridge needs a paid Proton plan and runs on Windows, macOS and Linux. On phones, use the Proton Mail app.
• The server is your own computer (127.0.0.1). The exact ports and security are shown in Bridge; use what it shows if they differ from this table.
• Paid plans with a custom-domain address can also create SMTP tokens to send from devices or websites through smtp.protonmail.ch.

How to set it up in a mail app

1. Open your mail app and choose to add an account. If it offers "Other", "Manual setup" or "Advanced", pick that.
2. Choose IMAP (recommended) or POP.
3. Enter the incoming and outgoing servers, ports and security from the table above.
4. Use the username and password described below.
5. Turn on "Outgoing server requires authentication" and use the same username and password.

If it doesn't work

Connection refused

Bridge must be open and signed in on the same computer as your mail app.

Certificate warning

Bridge uses its own certificate. Your mail app may ask you to trust it once.

Getting a bounce with a code like 550 or 5.7.26 when you send? Look it up in the SMTP error code library.

More help: Proton Mail guides.

Questions people ask

Can I use Proton Mail with Outlook or Thunderbird?

Yes, with Proton Mail Bridge on a paid plan.

Does Proton Mail support IMAP on the free plan?

No. IMAP access through Bridge needs a paid plan.