Render25 — High-performance transactional email platform. Now available.
SMTP

SMTP Relay

Connect any SMTP-compatible application, framework, or mail client to Render25 for reliable, authenticated email delivery.


Connection Settings

SettingValue
Hostsmtp.render25.com
Port (TLS)587
Port (SSL)465
EncryptionSTARTTLS or SSL/TLS
AuthenticationPLAIN / LOGIN

Authentication

Use your Render25 account email as the SMTP username and an API key as the password. Do not use your actual account password.

FieldValue
Username[email protected]
PasswordYOUR_API_KEY

Tip

Generate a dedicated API key with only the email:send scope for your SMTP relay credentials. This limits blast radius if the key is ever compromised.

TLS Configuration

Example using Node.js Nodemailer with STARTTLS on port 587:

nodemailer.config.ts
import nodemailer from "nodemailer";

const transporter = nodemailer.createTransport({
  host: "smtp.render25.com",
  port: 587,
  secure: false, // Use STARTTLS
  auth: {
    user: "[email protected]",
    pass: process.env.RENDER25_API_KEY,
  },
});

await transporter.sendMail({
  from: "[email protected]",
  to: "[email protected]",
  subject: "Hello from Nodemailer",
  html: "<p>Sent via SMTP relay</p>",
});

Example using Python smtplib with SSL on port 465:

smtp_send.py
import smtplib
import ssl
from email.mime.text import MIMEText

msg = MIMEText("<p>Hello!</p>", "html")
msg["From"] = "[email protected]"
msg["To"] = "[email protected]"
msg["Subject"] = "Test from Python"

context = ssl.create_default_context()
with smtplib.SMTP_SSL("smtp.render25.com", 465, context=context) as server:
    server.login("[email protected]", "YOUR_API_KEY")
    server.send_message(msg)