capitandavide/proton-bridge repository overview

⁠Proton IMAP/SMTP Bridge (headless, Alpine)

Minimal, headless Proton Mail Bridge⁠ container built from source on an Alpine Linux. The result is a small image that's ideal for self-hosting on your OpenWrt router or any low-resource home server, letting LAN clients use Proton Mail over plain IMAP/SMTP with STARTTLS.

• Minimal: multi-stage build, Alpine runtime, stripped binaries
• Multi-arch: linux/arm64 and linux/amd64
• Router-friendly: designed for OpenWrt-class devices
• Stateless image: vault, keyring, password-store, and TLS certs live in external volumes

Image tags follow the upstream Bridge version (e.g. 3.25.0); latest tracks the most recent release.

⁠Usage

One-time interactive setup (log in to Proton, then import the generated cert with cert import /certs/cert.pem /certs/key.pem):

docker run --rm -it \
  -e BRIDGE_LAN_IP=192.168.2.1 \
  -v proton-bridge-data:/root \
  -v proton-bridge-certs:/certs \
  capitandavide/proton-bridge

Run as a daemon:

docker run -d --name proton-bridge \
  -e BRIDGE_LAN_IP=192.168.2.1 \
  -p 1143:143 -p 1025:25 \
  -v proton-bridge-data:/root \
  -v proton-bridge-certs:/certs \
  --restart=unless-stopped \
  capitandavide/proton-bridge

BRIDGE_LAN_IP (default 127.0.0.1) is the host's LAN IP, added as a SAN to the self-signed TLS certificate generated on first run — set it so networked clients can validate the cert. It is only read on first run. This option is required when other clients connect over the network.

Clients connect to <host-ip>:1143 (IMAP) and <host-ip>:1025 (SMTP) with STARTTLS, using the credentials shown by the Bridge CLI info command:

docker exec proton-bridge sh -c 'printf "info\n" > /tmp/faketty'
docker logs proton-bridge

Note: Proton Mail Bridge requires a paid Proton Mail plan.

⁠Links

• GitHub repository⁠