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Standard SMTP

Works with any SMTP client or library

TLS Encryption

Secure connections with STARTTLS

High Deliverability

DKIM signed, SPF aligned

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SMTP Settings

Connect to Unosend’s SMTP relay using these credentials:
SettingValue
Hostsmtp.unosend.co
Port (STARTTLS)587
Port (SSL/TLS)465
Usernameunosend
PasswordYour API Key (e.g., un_abc123...)
Use your Unosend API key as the SMTP password. Get your API key from the dashboard.

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Code Examples

const nodemailer = require('nodemailer');

const transporter = nodemailer.createTransport({
  host: 'smtp.unosend.co',
  port: 587,
  secure: false, // Use STARTTLS
  auth: {
    user: 'unosend',
    pass: 'un_YOUR_API_KEY_HERE'
  }
});

async function sendEmail() {
  const info = await transporter.sendMail({
    from: '[email protected]',
    to: '[email protected]',
    subject: 'Hello from Unosend!',
    html: '<h1>Welcome!</h1><p>Your email was sent via Unosend SMTP.</p>'
  });

  console.log('Message sent:', info.messageId);
}

sendEmail();

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DNS Setup (Custom Domain)

To send from your own domain with best deliverability, add these DNS records:

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SPF Record

TXT Record
Type: TXT
Name: @
Value: v=spf1 include:unosend.co ~all

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DKIM Record (Optional)

Get your DKIM record from the Domains section in your dashboard.
TXT Record
Type: TXT
Name: _dmarc
Value: v=DMARC1; p=none; rua=mailto:[email protected]

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Troubleshooting

Make sure you’re using your API key (starts with un_) as the password, not your account password.
Check if your firewall allows outbound connections on port 587 or 465.
Ensure your system’s CA certificates are up to date. Our server uses Let’s Encrypt.

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Rate Limits

SMTP connections are subject to the same rate limits as the REST API:
  • Free: 100 emails/day
  • Pro: 50,000 emails/month
  • Scale: 200,000 emails/month