Best 4 SMTP Relay Services in 2026: Compare Pricing and Features

Introduction

Amazon SES is the strongest overall pick for an smtp relay service if you need a direct SMTP interface and TLS-encrypted connections. This roundup compares four services for transactional and marketing email, including how you can send, what reporting they offer, and which setups they may suit.

Quick comparison table

1. Amazon Simple Email Service

Best for: Teams that want a flexible, application-friendly relay.

Amazon Simple Email Service lets you send email from applications and existing mail servers through an SMTP interface. Its main advantage is direct SMTP access, with support for TLS-encrypted connections.

SES can work well for teams connecting an application or mail system to a relay. Setup may be more comfortable for people who know their way around email infrastructure. If you’d rather have a more guided workflow, factor that in before choosing.

2. Brevo SMTP

Best for: Businesses that want relay sending with reporting and analytics.

Brevo SMTP sends transactional email from websites, apps, email clients, and custom mail transfer agents. It also includes reporting and analytics, so teams can review their sending activity.

Support for several sending sources gives businesses flexibility when multiple systems send transactional messages. Still, it may not suit every workload. Compare its reporting and configuration options with the way your current systems send email.

3. Mailjet Email API

Best for: Teams that want both SMTP relay and an email API.

Mailjet Email API supports marketing and transactional email through compatible clients, software, and mail transfer agents. Its key distinction is that it offers both an SMTP relay and an email API.

That can suit a team deciding whether to send through an existing SMTP-compatible system or connect through an API. Check which option fits your application and how much maintenance you’re comfortable with before settling on a setup.

4. Elastic Email SMTP Service

Best for: Senders who want delivery insights and multiple credentials.

Elastic Email SMTP Service relays email from a domain and provides delivery-performance insights. It also lets you configure multiple SMTP credentials.

Separate credentials can help when a team has several sending systems or needs to manage access across its setup. Before choosing, check how its credential management fits with your applications and mail infrastructure.

How we picked these tools

This shortlist covers services that explicitly offer SMTP relay or SMTP sending. We looked at how they support sending from applications, websites, email clients, and mail servers, as well as features such as TLS support, analytics, delivery insights, and credential options.

This comparison focuses on features. It doesn’t mean every provider will suit every sending volume or configuration. Check current plans, limits, and technical requirements with each provider before making a choice.

Frequently asked questions

What is an SMTP relay?

An SMTP relay passes outgoing email from an application or mail system to its destination. It handles message delivery, unlike an email client or inbox, which gives you a place to read and manage mail.

When should a business use one?

Businesses often use SMTP relays to send transactional messages from websites and apps, such as account or order emails. Some providers also support marketing email, depending on the service and its configuration.

What should I compare?

Look at SMTP compatibility, security options, reporting, credential management, and how well the service fits your existing systems. Verify current pricing and sending limits with each provider, since both can vary by plan and use.

Do SMTP relays support TLS?

TLS encrypts the connection between a sender and a relay when configured properly. The details here confirm TLS support for Amazon SES. Check the other providers’ current security options before choosing.

The verdict

Amazon SES is the strongest overall pick based on its direct SMTP interface and TLS-encrypted connections. Brevo SMTP is a good runner-up if reporting and analytics matter to your team. Mailjet is worth considering if you want both an SMTP relay and an email API. Choose based on your sending workflow, reporting needs, and configuration requirements.