How Email Suppression Lists Protect Your Sender Reputation

Milos Ilic — Fri, 26 Jun 2026 20:46:46 +0000

Every bounced email is a signal to Gmail and Outlook that something is wrong with your sending practices. Too many bounces and your emails start landing in spam — or stop being delivered entirely.

We just shipped suppression lists on PrimeTimeMail.

What it does

When an email bounces or a recipient marks it as spam, that address is automatically added to your suppression list. Any future send attempts to that address are blocked before the email is ever sent.

Why it matters

Mailbox providers track your bounce rate. Above 2-3% and you're treated as a low-quality sender. The consequences are immediate — spam folder routing, temporary blocks, or permanent blacklisting.

Managing it via API

# List suppressed addresses
curl https://api.primetimemail.com/v1/suppressions \
  -H "X-API-Key: ptm_live_..."

# Add manually
curl -X POST https://api.primetimemail.com/v1/suppressions \
  -H "X-API-Key: ptm_live_..." \
  -d '{"email": "bad@example.com", "reason": "manual"}'

# Remove
curl -X DELETE https://api.primetimemail.com/v1/suppressions/bad@example.com \
  -H "X-API-Key: ptm_live_..."

Free on all plans at primetimemail.com

How to Send Transactional Emails in Node.js (2026 Guide)

Milos Ilic — Wed, 24 Jun 2026 19:58:07 +0000

Every app that has users needs to send emails — welcome messages, password resets, order confirmations. This guide shows you how to set it up cleanly in Node.js using a REST API, with real code you can copy and run today.

What is a transactional email?

Transactional emails are triggered by user actions — not marketing campaigns. Examples include:

Welcome email when someone signs up
Password reset link
Order confirmation
Account verification
Invoice or receipt

Unlike newsletters, these emails are sent one at a time in response to something the user did. They have very high open rates and are critical to your product experience.

Prerequisites

Node.js 18+ installed
A PrimeTimeMail account (free, no card required)
Your API key from the dashboard

Step 1 — Get your API key

Sign up at primetimemail.com. After email verification, your API key arrives in your inbox. It looks like ptm_live_.... Keep it safe — treat it like a password.

Step 2 — Send your first email

No SDK needed. Use the native fetch API built into Node.js 18+:

const response = await fetch('https://api.primetimemail.com/v1/send', {
  method: 'POST',
  headers: {
    'X-API-Key': 'ptm_live_your_key_here',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    to: 'user@example.com',
    subject: 'Welcome to MyApp!',
    html: '<h1>Welcome!</h1><p>Thanks for signing up.</p>'
  })
});

const data = await response.json();
console.log(data); // { id: '...', status: 'sent' }

Step 3 — Store your API key safely

Never hardcode your API key. Use environment variables:

# .env
PTM_API_KEY=ptm_live_your_key_here

import 'dotenv/config';

const response = await fetch('https://api.primetimemail.com/v1/send', {
  method: 'POST',
  headers: {
    'X-API-Key': process.env.PTM_API_KEY,
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    to: 'user@example.com',
    subject: 'Welcome!',
    html: '<p>Thanks for signing up.</p>'
  })
});

Step 4 — Create a reusable email helper

// lib/email.js
export async function sendEmail({ to, subject, html }) {
  const res = await fetch('https://api.primetimemail.com/v1/send', {
    method: 'POST',
    headers: {
      'X-API-Key': process.env.PTM_API_KEY,
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({ to, subject, html })
  });

  if (!res.ok) {
    const err = await res.json();
    throw new Error(err.error || 'Failed to send email');
  }

  return res.json();
}

Now use it anywhere:

await sendEmail({
  to: user.email,
  subject: 'Welcome to MyApp!',
  html: `<h1>Hey ${user.name}!</h1><p>Thanks for signing up.</p>`
});

Step 5 — Handle errors properly

try {
  await sendEmail({
    to: newUser.email,
    subject: 'Verify your email',
    html: `<a href="${verifyUrl}">Verify your email →</a>`
  });
} catch (error) {
  console.error('Failed to send welcome email:', error.message);
  // Don't crash the signup flow — log it and move on
}

Tip: Don't block your signup flow on email sending. Send it async, catch errors silently, and log them for monitoring.

Step 6 — Use custom From name

Set a friendly sender name in your dashboard under Settings → From Name. Instead of noreply@primetimemail.com, your users will see MyApp <noreply@yourdomain.com>.

Full working example

import express from 'express';
import 'dotenv/config';

const app = express();
app.use(express.json());

async function sendEmail({ to, subject, html }) {
  const res = await fetch('https://api.primetimemail.com/v1/send', {
    method: 'POST',
    headers: {
      'X-API-Key': process.env.PTM_API_KEY,
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({ to, subject, html })
  });
  if (!res.ok) throw new Error('Email failed');
  return res.json();
}

app.post('/register', async (req, res) => {
  const { email, name } = req.body;

  try {
    await sendEmail({
      to: email,
      subject: 'Welcome to MyApp!',
      html: `<h1>Hey ${name}!</h1><p>Your account is ready.</p>`
    });
  } catch (err) {
    console.error('Welcome email failed:', err.message);
  }

  res.json({ success: true });
});

app.listen(3000);

What's next?

Add webhooks to track bounces and complaints
Set up a custom sending domain for better deliverability
Monitor your email logs in the dashboard

Built with PrimeTimeMail — transactional email API for developers. 3,000 emails/month free.

DEV Community: Milos Ilic