SMTP relay

Send through Ritto Mail from any app that speaks SMTP — Supabase, n8n, WordPress, Nodemailer and more.

Apps that can't call an HTTP API can send through the Ritto Mail SMTP relay. Messages go through the same pipeline as the Emails API: same domains, suppressions, webhooks, logs and plan limits.

Connection settings

Setting	Value
Host	`smtp.ritto.email`
Port	`465`, `587` or `2587` — see the table below
Username	`ritto-mail`
Password	any API key from API keys in the dashboard (`rm_…`)

Port	Security	When to use it
`465`	SSL/TLS (implicit TLS — encrypted from the first byte)	Apps that ask for "SSL", "SSL/TLS" or `secure: true`, such as Supabase
`587`	STARTTLS (plain connection upgraded to TLS before authentication)	Apps that ask for "STARTTLS" or "TLS"
`2587`	STARTTLS	Fallback when your network blocks 587

Every port requires TLS before authentication; the API key never travels in the clear. The From address must use a domain that is verified in the same team as the API key.

Migrating from Resend

If your app already sends through smtp.resend.com, change only three fields:

Field	Resend	Ritto Mail
Host	`smtp.resend.com`	`smtp.ritto.email`
Port	`465`	`465` (unchanged) — `587` also works
Username	`resend`	`ritto-mail`
Password	your Resend API key (`re_…`)	your Ritto Mail API key (`rm_…`)

Security stays the same (SSL/TLS on 465, STARTTLS on 587). Verify your sending domain in Domains before switching, or messages are rejected.

Supabase (Auth emails)

In Supabase → Project Settings → Authentication → SMTP Settings, enable custom SMTP and fill in:

Sender email: no-reply@yourdomain.com (a verified domain)
Host: smtp.ritto.email · Port: 465
Username: ritto-mail · Password: your API key

Supabase uses implicit TLS on 465, the same setting Resend recommends; 587 also works.

Nodemailer

import nodemailer from "nodemailer";

// Port 465: implicit TLS.
const transport = nodemailer.createTransport({
  host: "smtp.ritto.email",
  port: 465,
  secure: true,
  auth: { user: "ritto-mail", pass: process.env.RITTO_MAIL_API_KEY },
});

// Or port 587: STARTTLS.
// nodemailer.createTransport({ host: "smtp.ritto.email", port: 587, secure: false, requireTLS: true, auth: { ... } });

await transport.sendMail({
  from: "Acme <orders@acme.dev>",
  to: "jane@example.com",
  subject: "Your order is confirmed",
  html: "<p>Thanks for your order!</p>",
});

Use the generic SMTP credential of the tool with the settings above. Pick SSL/TLS with port 465, or STARTTLS (sometimes labelled "TLS") with port 587. Mixing them (SSL on 587, STARTTLS on 465) fails at connect time.

Troubleshooting

Connection hangs or "wrong version number" / handshake errors: the security mode doesn't match the port. Use SSL/TLS with 465 and STARTTLS with 587 or 2587.
Connection times out on 587: some hosting providers block outbound 587. Use port 465 or 2587.
Authentication failed: the password must be a valid, non-revoked API key; the username is always ritto-mail (not resend).
Rejected sender: verify the From domain in Domains first.
No active plan: sending requires an active subscription — see Billing.