hydroxide

A third-party, open-source ProtonMail bridge. For power users only, designed to run on a server.

hydroxide supports CardDAV, IMAP and SMTP.

Rationale:

• No GUI, only a CLI (so it runs in headless environments)
• Standard-compliant (we don't care about Microsoft Outlook)
• Fully open-source

Setup

Go

hydroxide is implemented with Go. Head to Go website for setup information.

Install and Setup

Install hydroxide

go get github.com/emersion/hydroxide/cmd/hydroxide

Your credentials will be stored on disk encrypted with a 32-byte random password. When configuring your client, you'll need this password.

hydroxide auth <username>

Usage

hydroxide can be used in multiple modes.

CardDAV

You must setup an HTTPS reverse proxy to forward requests to hydroxide.

hydroxide carddav

Tested on GNOME (Evolution) and Android (DAVDroid).

IMAP

For now, it only supports unencrypted local connections.

hydroxide imap

SMTP

For now, it only supports unencrypted local connections.

hydroxide smtp

License

MIT