Choose a mail relay

A relay is a mail server that takes your mail after a sign-in and delivers it for you. This page tells you whether you need one, and what to check when you pick one.

When you need one

It depends on your answer to Host email on this server?:

• If your mail stays with your current provider (Proton Mail, Google Workspace, Microsoft 365, Fastmail…), always. Everything Eigen sends goes through the relay: two-factor codes by email, guest sign-in codes, invitations, share and access-request notifications, and calendar invitations and replies. Without a relay, every one of those fails.
• If Eigen hosts your mail, only when your provider blocks outgoing port 25. Otherwise Eigen's mail server delivers straight to the receiving server. Hetzner and DigitalOcean block port 25 on new accounts. Ask them to open it, or send through a relay.

Which relays work

Anything that takes mail over SMTP with a user name and password:

• A mail service like Brevo, Postmark, Mailgun, SendGrid, or Amazon SES. Most have a free tier of a few hundred mails a day.
• The SMTP server of your current mail provider: Google Workspace, Gmail with an app password, Fastmail, or your internet provider.
• A mail server you run yourself.

Enter it at setup

Answer the relay question as host:port, like smtp-relay.brevo.com:587. Setup then asks for the user name and the password. To change the relay later, run ./eigen setup again.

Port 465 means the connection is encrypted from the start. Any other port starts plain and switches to encryption. With a user name, the connection must be encrypted, so the password never travels in the clear. When your mail stays with your current provider and the relay has a user name, Eigen also checks the relay's certificate.

Which addresses it must accept

Check which sender addresses the relay lets you use.

• If your mail stays with your current provider, Eigen sends from one address, the sender address in Admin Settings, unless you turn on Relay sends as users. One mailbox is enough, a Gmail account included, as long as it may send from that address. See Keep your existing mail.
• If Eigen hosts your mail, every user's mail goes out through the relay from their own address. The relay must accept every address on your mail domain. A mail service does, once you have verified the domain. A personal Gmail account does not: Gmail rewrites the sender to the account itself, so mail from Jane would arrive as sent by you. Google Workspace has an SMTP relay service that sends for a whole domain.

Use the mail server on this machine

If your mail stays with your current provider and you already run a mail server on the same machine, outside Docker, that mail server can be the relay. Answer host.docker.internal:25, which is Docker's name for the machine Eigen runs on. That mail server must:

• Listen on 0.0.0.0 or on the gateway of Eigen's Docker network, not only on 127.0.0.1. The network is EIGEN_SUBNET in .env.production.
• Allow relaying from that network.