Twilio SendGrid Email API

SMTP relay service

Send email reliably at scale with our cloud-based SMTP relay service. Get fast integration, robust APIs, and expert support—no email servers required. Join businesses who trust Twilio’s tested infrastructure to deliver over 190 billion emails monthly.

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Scale your SMTP sending with confidence

The reliability of enterprise email infrastructure without the complexity. Our SMTP relay service combines powerful delivery features with developer-friendly tools.

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    Send reliably at scale

    Deploy globally distributed infrastructure backed by Twilio’s proprietary MTA that handles billions of emails monthly with industry-leading uptime and delivery rates.

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    Integrate quickly with flexible options

    Choose from our feature-rich Mail/Send API, standard SMTP relay, or enhanced SMTP API. Get started in minutes with comprehensive documentation and SDKs.

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    Monitor and optimize delivery

    Track email performance in real-time with detailed analytics on delivery rates, bounces, and engagement.

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    Protect your sender reputation

    Benefit from automated IP warmup, spam monitoring, and reputation tracking tools to maintain your sending reputation and improve deliverability.

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    Access 24/7 expert support

    Get help when you need it from our team of email experts. We provide technical guidance and strategic advice to optimize your email program.

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    Maintain security and compliance

    Secure your emails program with enterprise-grade features including TLS encryption, IP access management, and authentication protocols.

How the SMTP relay service works

Choose your preferred integration method and start sending emails in minutes.

 

Illustration of SMTP relay service configuration using provided credentials and API key, supporting multiple email clients.

Configure

Set up your SMTP credentials

Create your SendGrid account and generate secure SMTP credentials. Configure your sending domain and verify ownership to establish your identity.

Connect

Update your email client settings

Add SendGrid's SMTP server settings to your email client, application, or content management system.

Send

Start sending emails

Send your first email through our SMTP relay. Monitor delivery in real-time through your SendGrid dashboard and access detailed analytics about your email performance.

Email SMTP relay pricing

Access SMTP relay with Email API plans

Get started with our Email API plan that includes SMTP relay service, plus powerful APIs, real-time analytics, and expert support. Scale easily with our flexible pricing tiers.

Simple, usage-based pricing

Start sending for free with 100 emails per day. Then pay as you go starting at $19.95/month for up to 100,000 emails, with volume discounts automatically applied as you scale.

 

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Resources to help get you started

An Open book

Docs

Real Time Email Address Validation - API Reference

Learn how to get started with the API.
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Blog

Bulk Email Address Validation in Node.js

See how to integrate bulk email address validation using Node.js.
An Open book

Docs

Twilio Docs

Check out API reference documentation, quickstarts, SDKs, and code samples.

Do more with your email sending

Build a comprehensive email infrastructure with powerful tools.

  • Dynamic Templates

    Create and manage reusable email templates with dynamic content, conditional formatting, and testing previews.

  • Email testing

    Preview how your emails render across inbox providers and devices. Test for spam filter triggers, broken links, and load time issues.

  • Email Validation API

    Verify email addresses in real-time to catch typos and invalid addresses before sending.

  • Event Webhook

    Track email engagement in real-time with detailed event data for opens, clicks, bounces, and more.

Get started for free. No credit card required.

Start with 100 free emails per day. Then scale as your needs grow.

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