mailintel
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privacyprotonmailapp password

Proton Mail IMAP and SMTP settings

Proton Mail is encrypted at rest and does not speak plain IMAP or SMTP. Local access goes through Proton Mail Bridge, which exposes a loopback server.

Connection
IMAP host
127.0.0.1

port 1143 · None (local)

SMTP host
127.0.0.1

port 1025 · None (local)

Username

your full email address
password: app-specific
Setup

Connect in three steps

  1. 1

    Install Proton Mail Bridge on the machine that will connect.

  2. 2

    Unlock Bridge and copy the generated IMAP/SMTP credentials.

  3. 3

    Point your client at 127.0.0.1:1143 (IMAP) and 127.0.0.1:1025 (SMTP).

Watch out

What usually breaks

  • There is no hosted IMAP endpoint. The only supported path is the local Bridge.

  • Bridge is a paid feature (Mail Plus / Proton Unlimited).

  • The default Bridge ports are 1143 and 1025, but Bridge can be configured to use others.

Detect it

Resolve it instead of hardcoding it

A custom domain on Proton Mail has the same MX infrastructure as the consumer product. That is what mailintel reads.

proton-mail.ts
import { mailintel } from "mailintel";

const result = await mailintel("[email protected]");

result.provider;              // "protonmail"
result.connection.imap;       // { host: "127.0.0.1", port: 1143, security: "none" }
result.connection.smtp;       // { host: "127.0.0.1", port: 1025, security: "none" }
result.connection.username;   // "[email protected]"
FAQ
What is Proton Mail's IMAP server?+

127.0.0.1 on port 1143 using None (local). The username is the full email address, and an app password is required when two-factor authentication is enabled.

What is Proton Mail's SMTP server?+

127.0.0.1 on port 1025 using None (local). Most clients also accept the alternate submission port with STARTTLS.

Does Proton Mail need an app password?+

Yes, in practice. Proton Mail rejects normal account passwords for IMAP and SMTP once 2FA is on, so generate an app-specific password.