Deliver transactional and marketing emails with 99.9% deliverability

Mail Relay delivers transactional emails at scale with 99.9% deliverability. Send password resets, receipts, notifications, and marketing emails through a single API. Our infrastructure handles billions of emails monthly with sub-second latency.

Built for developers who need reliability. Mail Relay includes bounce handling, spam score checking, and automatic list management. Monitor email performance with detailed analytics including open rates, click rates, and delivery status.

Features

Template System

Design emails with our drag-and-drop builder or use Handlebars templates in code. Version control your templates and A/B test subject lines automatically.

Smart Sending

Mail Relay optimizes send times based on recipient timezone and historical engagement. Emails arrive when users are most likely to open them.

import { MailRelay } from '@mailrelay/sdk';

const mail = new MailRelay({
  apiKey: process.env.MAILRELAY_KEY
});

// Send transactional email
await mail.send({
  to: 'user@example.com',
  template: 'welcome',
  variables: {
    name: user.name,
    activationLink: link
  }
});

// Send with attachments
await mail.send({
  to: 'user@example.com',
  subject: 'Your Invoice',
  template: 'invoice',
  attachments: [{ filename: 'invoice.pdf', content: pdfBuffer }]
});

import { MailRelay } from '@mailrelay/sdk';

const mail = new MailRelay({
  apiKey: process.env.MAILRELAY_KEY
});

// Send transactional email
await mail.send({
  to: 'user@example.com',
  template: 'welcome',
  variables: {
    name: user.name,
    activationLink: link
  }
});

// Send with attachments
await mail.send({
  to: 'user@example.com',
  subject: 'Your Invoice',
  template: 'invoice',
  attachments: [{ filename: 'invoice.pdf', content: pdfBuffer }]
});

import { MailRelay } from '@mailrelay/sdk';

const mail = new MailRelay({
  apiKey: process.env.MAILRELAY_KEY
});

// Send transactional email
await mail.send({
  to: 'user@example.com',
  template: 'welcome',
  variables: {
    name: user.name,
    activationLink: link
  }
});

// Send with attachments
await mail.send({
  to: 'user@example.com',
  subject: 'Your Invoice',
  template: 'invoice',
  attachments: [{ filename: 'invoice.pdf', content: pdfBuffer }]
});

Deliverability

Mail Relay maintains strong sender reputation by monitoring bounces, complaints, and engagement rates. Our team works directly with ISPs to ensure inbox placement. All emails are authenticated with SPF, DKIM, and DMARC.

Handle unsubscribes automatically with built-in compliance tools. Track suppression lists across your account. Get real-time webhook notifications for bounces, complaints, and engagement events. Integrate with customer support tools to manage email issues.