Every Eurobase project starts on the shared platform email sender (Scaleway TEM, EU-sovereign, but capped per project). When you outgrow that cap, or want emails to come from your own domain with your own sender reputation, you can bring your own SMTP provider.

Once configured and verified, all auth emails for your project (verification, password reset, magic link) route through your SMTP instead of the platform sender. The platform "emails per hour" cap no longer applies to your sends — you're now bounded by your provider's own limits.

Where to find it

In the console: Auth → SMTP tab. Only project admins can configure this — members with the "developer" or "viewer" role can't see the credentials. If a project drops back to Free, a sender saved earlier is kept but not used, and auth emails go out through Eurobase's sender; after upgrading again, run a test send to use it again.

What you'll need from your provider

• Host — the SMTP server's public host name (e.g. smtp.brevo.com, smtp-relay.brevo.com, in.mailjet.com).
• Port — 587 (STARTTLS) or 465 (TLS); 2525 if your provider offers it. Port 25 isn't accepted: it's for server-to-server delivery, not for sending from an account.
• Username + Password (required) — the SMTP credentials from your provider. Often the username is an API key identifier and the "password" is the secret half.
• From address — the email address auth messages will come from (e.g. noreply@yourdomain.com). Must be a domain you've verified with your provider.
• From name — optional display name (e.g. "LexVault").
• Encryption — STARTTLS for port 587 (most common), TLS for port 465. Unencrypted connections aren't supported.

Eurobase connects only to servers on the public internet: host names that only resolve inside a network (such as mail.local) and private or internal IP addresses are refused. When you change the host, port or username, enter the password again.

Setting it up

1. Open Auth → SMTP.
2. Fill in the form with the details above. Hit Save. The password is encrypted at rest with your project's per-tenant key — we never store or transmit it in plaintext after this point, and the API never returns it.
3. You'll see an amber Not verified badge. Until you verify by sending a test, the project keeps using the platform sender. This is intentional — we'd rather fail loudly at setup than silently at first signup.
4. Type an address you can check (your own works) into Send test, hit the button. Within seconds you should receive a small "your custom SMTP is wired up correctly" message.
5. The badge flips to a green Verified. From this point onward your project's auth emails route through your provider.

If the test fails

The console first says what probably went wrong and what to change, then shows the exact error your provider returned. Common cases:

• No answer / timeout — wrong host or port, or the server only accepts connections from its own network. If Eurobase itself can't make outgoing SMTP connections at the moment, the SMTP tab shows a notice saying so.
• Connection refused — wrong port. Most providers use 587 with STARTTLS, or 465 with TLS.
• “Doesn't use TLS from the start” / no greeting — the encryption doesn't match the port: 465 needs TLS, 587 needs STARTTLS.
• Login rejected — wrong username or password; some providers need an app-specific password for SMTP.
• From address refused — the From address must be one your SMTP account may send as.

Once the sender is in use, Auth → Email log shows every auth email and whether your server took it, with the same explanations when it didn't.

If you were already verified and a test starts failing, the project keeps using the last-known-good config until either a successful retest or a config change. Two things do switch it back to the platform sender until you run a new test send: the project leaving the Pro plan, and a saved sender that no longer meets the rules above (a public host, a submission port, STARTTLS or TLS, a login) — fix its settings, then run a new test send. A transient blip from your provider doesn't silently regress your project to the platform sender behind your back.

Sovereignty advisory

Eurobase itself runs entirely on EU-sovereign infrastructure (Scaleway, France). If you configure a US-based SMTP provider (SendGrid, Mailgun, Postmark, Amazon SES, Mandrill, SparkPost, SMTP.com), the console shows an amber advisory: your auth email content will leave the EU jurisdiction even though the rest of your project doesn't.

This is your call — it's not a block. EU-based alternatives worth knowing: Scaleway TEM, Brevo (FR), Mailjet (EU), Mailtrap EU.

What stays on the platform sender

Custom SMTP routes your project's auth emails (verification, password reset, magic link). It does not route:

• Console password resets to you (the Eurobase account owner) — those are platform-level and always come from us.
• Broadcast emails sent via the superadmin announcement tool.

Everything that represents your tenant goes through your sender; everything that represents us stays on the platform sender. The rule is simple and the routing is automatic — you don't need to do anything special.

Disconnecting

Hit Disconnect at any time to fall back to the platform sender. The sealed password is wiped from our database. You can re-add later with fresh credentials.