SAIDR

Connect Proton Mail

Proton doesn't expose plain SMTP publicly — you'll run Proton Bridge locally and point SAIDR at that.

Using Gmail or Microsoft 365 instead? Connect via OAuth at Settings → Integrations — one click, no app password. This guide covers Proton Mail, which doesn't support OAuth in SAIDR yet.
Proton Bridge only works for paid Proton plans (Mail Plus, Unlimited, Business). Free Proton accounts can't be used as an SMTP sender.

1 · Install Proton Bridge

  1. 1
    Download Proton Bridge from proton.me/mail/bridge for macOS, Windows, or Linux.
  2. 2
    Install it and sign in with your Proton account credentials.
  3. 3
    Wait for the initial sync — it may take a few minutes on first run.

2 · Get the Bridge SMTP credentials

  1. 1
    Open Proton Bridge → select your account → Mailbox details.
  2. 2
    Bridge shows an SMTP host (usually 127.0.0.1), port (usually 1025), username (your full Proton address), and a randomly generated password.
  3. 3
    Copy the randomly generated password — this is not your Proton login password.

3 · Paste into SAIDR

Catch: SAIDR runs in the cloud. Proton Bridge runs on your laptop. For the SMTP connection to work, SAIDR needs to reach your laptop — which means Bridge can't just run on 127.0.0.1. You have two options:
  • (A) Self-host SAIDR on your network alongside Bridge — the enterprise path. Contact us about an on-prem deployment.
  • (B) Use a paid Proton Business / Unlimited plan with a custom domain and use that domain's SMTP through a relay like SMTP2GO or Postmark. Point MX at Proton; point SMTP at the relay.

In practice, most SAIDR customers on Proton switch their sending domain to a Google Workspace or Microsoft 365 mailbox specifically for outbound, and keep Proton for incoming. Cold-outreach deliverability is much better on a warmed Workspace / M365 domain anyway.

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