Top 11 Most Popular Transactional Email Service Providers in 2026

List of the best free Transactional Email API Service providers with detailed review and comparison:

The white label Email API services are used to send transactional emails, newsletters, marketing emails, and promotional emails.

Examples of transactional emails are the emails that we receive about social media updates, password resets, the creation of accounts, etc.

These transactional emails are generally sent by integrating with SMTP (Simple Mail Transfer Protocol). It is a TCP/IP protocol which is used for sending and receiving email.

What is Email API Service?

It is a simple process to send and receive a single email.

But it becomes a difficult task when it comes to sending multiple emails. Thus, Email API services help in this process. These services not only help in sending and receiving emails but also in creating emails as well. It takes care of the engagement factor.

These services allow you to track the sent email and thereby take care of the deliverability factor too. This means that it will increase the chances of your email to get delivered in the inbox and not as a spam.

Most of the top Transactional Email Services for developers which we are going to discuss in this article are cloud-based. So you can manage this process of emails through app or website and you will not have to manage the servers.

Best Transactional Email Service Providers

Given below is the list of the most popular Email API services for delivering transactional emails fast and reliably.

Comparison of the Top Email API Services

Let’s Explore!!

#1) SMTP

Price: You get four subscription plans to choose from. The essential plan costs $25 for 50000 emails per month. The starter plan costs $80 for 100,000 emails per month. Growth plan costs $300 for 500000 emails per month. The Business plan costs $500 for 1,000,000 emails per month.

SMTP offers robust transactional and email API relay services. The service is bolstered by an infrastructure that can be scaled to meet your business’s specific email volume requirements. The service also benefits from being very responsive. You’ll experience 99% uptime with no latency at all.

This is essential if you expect impeccable deliverability rates, which is a quality all transactional email services must have. We also like that the tool proactively vets out spam from mailboxes to maintain a spotless delivery rate. Add to that, you get good in-house support that’s delivered by a team of seasoned email delivery experts.

Features:

• Email Relay API
• Shared and Dedicated IP
• Detailed Reporting
• In-House Expert Support

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#2) Klaviyo

Price: You can send up to 500 emails for free with Klaviyo. Its email-only plan will cost you around $45 per month, whereas its Email + SMS plan will cost you $60 per month. You can get a free demo of the tool upon request.

Klaviyo is a platform you can use to streamline your email and SMS marketing campaigns. Powered by Klaviyo’s built-in data platform, this solution lets you send personalized emails for each customer with ease. You can segment customers based on any piece of data, from any source, across all time. 

Klaviyo also facilitates over 350+ integrations. As such, you can rely on this data, pulled from across your tech stack, to send a variety of transactional emails. This includes shipping alerts, subscription reminders, emails based on purchase history, etc. The platform also lets you create flows for multiple channels, thus automatically sending emails based on real-time customer behavior. 

Features

• Drag-and-drop email builder
• Over 160 customizable email campaign templates
• Segment customers based on data pulled across all time
• Supports over 350+ built-in integrations
• Expand customer reach with cross-channel flows and campaigns. 
• AI-based testing to repair sender reputation.

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#3) GetResponse

Price: GetResponse offers the following plans:

• Starter: $19/month
• Marketer: $59/month
• Creator: $69/month

A custom enterprise plan and a 30-day free trial are also offered.

GetResponse is a software we’d recommend to creators and marketers who want to automate their email marketing efforts. The tool lets you easily set up transactional emails, which will be triggered based on user actions. You can set up automated emails to guide customers through a purchase. 

You can create and set all sorts of transactional emails with GetResponse. This includes abandoned cart emails, purchase confirmation emails, shipping notifications, etc. Creating transactional emails is also simpler with GetResponse because of its template library and AI-generative capabilities. 

Features:

• Over 200 professionally designed email templates that can be customized based on your preference. 
• AI-writing assistant powered by OpenAI. It can help you generate transactional emails. 
• Get real-time insight on email performance. 
• Set autoresponder emails, which will be triggered at a set time. 
• Set web push notifications for increased conversions.

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#4) Constant Contact

Price: Constant Contact charges its users based on how many contacts they want to accommodate. As such, there are two plans with the Core plan starting at $9.99/month.

The relatively more expensive Plus plan starts at $45/month and includes all the features of the Core plan alongside some advanced offerings. A 30-day free trial is also available.

Constant Contact is a platform we recommend precisely for its amazing transactional email technology that integrates seamlessly with Shopify. Boasting several pre-designed templates and an intuitive drag-and-drop builder, the platform makes it easier to create and send compelling transactional emails.

Moreover, the templates can be further customized to best complement your brand. The emails you create and send with Constant Contact have the ability to incite engagement between your prospects and your brand. The platform’s amazing automation capabilities also allow you to nurture leads, grow your newsletter, and help customers navigate your sales funnel.

Features:

• Drag and Drop email builder
• Segment Contact List
• Tons of pre-designed customizable transactional email templates
• Smooth Shopify integration.
• Insightful real-time reporting and analytics

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#5) HubSpot Email Marketing

Pricing: HubSpot has a free plan that also comes with a CRM, a form and popup builder, landing pages, live chat, chatbots, and a lot more tools to grow your business. The paid plans start at $50 per month.

HubSpot is a CRM platform that comes with a stack of marketing, sales, customer service, and operations software, all built on top of a powerful CRM.

The marketing software provides email marketing, forms, landing pages, automation, and many other complementary features. You can choose to use the platform as a whole, or choose and select your tools individually.

Because of its native integration with the HubSpot CRM, the email marketing tool lets you deeply customize your email campaigns. The CRM suite works seamlessly together to ensure a well-integrated, solid marketing campaign.

You can collect email addresses with a form and popup tool to grow your email list, collect them in a CRM, which automatically logs any relevant information you want to have about your contacts, which can be used in your emails.

Features:

• Aesthetic email template designs optimized for your goals.
• Easy-to-use drag-and-drop editor that gives you the flexibility to give your emails the look and feel you want.
• Email deliverability and conversion metrics to help you optimize your campaigns.
• Comes with a full stack of campaign tools such as landing pages, forms, popups, ads, and more.
• Marketing automation to do more with less work.

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#6) Mailjet

Price: Price depends on the number of emails you send per month. There is a free plan which allows you to send 6000 emails per month. Basic plan starts at $8.69 per month for 30000 emails. The price will increase accordingly as the number of emails grows.

Mailjet email service provides many features to create, manage, send, and optimize emails. This tool will allow you to personalize email templates. You will be able to work as a team on email design.

Features:

• Real-time collaboration.
• In-app commenting.
• Drag-and-drop editor to design the email.
• It provides in-depth analytics for the sent emails.

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#7) SendGrid

Price: Free plan, Essentials (Starts at $9.95/month), Pro (Starts at $79.95 per month), and Premier (Custom).

It is a cloud-based email delivery service. It provides fast and customizable integration. They offer a mobile app as well so you can share this single email platform with the team. It extends support through video tutorials, an online community, and documentation.

Features:

• Supports development frameworks and client libraries.
• It provides domain and link customization, regardless of the email being sent from shared IP pools and dedicated IP.
• Eliminate domain spoofing.
• Eliminate phishing emails.
• It provides security through two-factor authentication, API key permissions, IP access management, precise teammate permissions and much more.

Website: https://sendgrid.com/

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#8) Mailgun

Price: Price depends on the number of validations you require along with the number of emails sent per month. It is free for 10000 emails and 100 validations per month. The price will considerably go up when the number of emails and validations increase.

This transactional service is made for developers. It is useful to send, receive, and track emails. The service will scale as per your needs.

Features:

• It provides advanced email analytics.
• This analytics will allow you to track engagement metrics.
• It will provide better deliverability to emails and maximize the chances of the email to get delivered in the inbox.

Website: https://www.mailgun.com/

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#9) Amazon SES

Price: Price starts at $0.10 and it provides flexible pricing options.

It is an email sending and receiving platform. You can use this service to send transactional messages, marketing communications, notifications, and for receiving incoming email. It provides flexible pricing options. It has a flexible email receiving option.

You can decide which emails to accept.

Features:

• This service allows you to create an email template.
• Content filtering technologies.
• Dedicated IP addresses.
• It allows you to create rules for emails using the Configuration sets feature.

Website: https://aws.amazon.com/ses/

Check our Guide on Amazon SES Alternatives & Competitors

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#10) Mandrill

Price: Price is based on the number of blocks where Block refers to 25000 emails. For 1-20 blocks, the price will be $20 per block. For 21-40 blocks, the price will be $18 per block. As the number blocks increase, the price will go down accordingly.

Mandrill is a transactional email service for MailChimp users, provided by MailChimp. It can be used for data-driven emails like e-commerce & personalized one-to-one messages.

Features:

• It provides a searchable activity log.
• You can customize the tracking options.
• Based on the sender and template, an email will automatically get tagged.
• It allows you to generate user-friendly reports and track spam complaints.

Website: https://mandrill.com/

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#11) Aweber

Aweber makes sending transactional emails very convenient by allowing users to create customized emails. You get access to a massive library of pre-made email templates, which you can use to send relevant transactional emails.

You get to create cart abandoned emails, feedback emails, confirmation emails, notification emails, etc. which can be automated to reach the audience as a response to the action taken by them.

Features:

• Personalize your transactional emails with layouts, themes, stock images, and pre-made templates.
• Send targeted emails automatically at a scheduled time and date.
• Create subscriber segments based on user activity.
• Easy integration with several third-party applications.
• Comprehensive reporting and analytics.

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#12) InboxAlly

Price: InboxAlly offers multiple subscription plans to its users. The starter plan costs $149/month. On the other hand, its Plus and Premium plans cost $645/month and $1190/month respectively. A custom enterprise plan is also offered. You can also try the tool for free for 10 days.

While not specifically a transactional email service, InboxAlly is a tool you can use to improve the deliverability of your transactional emails. This tool teaches email sending services to understand that emails sent from your domain or IP are important to ensure they reach directly into an inbox. The tool basically keeps your emails away from Spam and Promotions folders.

InboxAlly can easily improve the deliverability of any IP or domain. It also helps you set your own sending schedule. You can set up multiple sender profiles to accommodate all of your IPs and Domains. The tool also makes it easier for you to track all the emails you’ve sent in the past 30 days via a compelling visual dashboard.

Features:

• Broadcast Auto Detect
• Visual Dashboard for Tracking email progress
• Set your own reporting time zone
• Set your own sending schedule
• Select a pre-set engagement profile or configure one yourself.

Website: https://www.inboxally.com/

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#13) Brevo

Price: Brevo has five plans including the Free plan, Lite ($25 per month), Essential ($39 per month), Premium ($66 per month), and Enterprise (Get a quote). A free plan will allow you to send 300 emails per day.

Brevo provides a complete all-in-one digital marketing toolbox. Brevo provides a solution for email marketing, SMS marketing, and Chat. It has functionalities for transactional email, segmentation, CRM, and marketing automation.

For more engagement, the tool will let you send marketing messages to a targeted audience. Brevo will let you choose the setup option from various options such as API, SMTP, Relay, eCommerce plugins, or marketing automation.

Features

• Brevo provides various professionally designed templates.
• The tool has a drag-and-drop editor to help you design a transactional email from scratch.
• Email deliverability experts will work to help you with reaching the email to the inbox.
• It provides statistics for engagement and deliverability.
• It has features for Landing pages, SignUp Forms, Facebook Ads, and Retargeting.
• Marketing Automation features will help you to boost the performance by automating the segmentation and marketing messages.

Website: https://www.brevo.com/

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Conclusion

Email API service plays a predominant role in today’s technological world.

We can conclude the Top Transactional Email API Services for developers article as all the tools are best and each one provides the best possible features. Most of the APIs are used by developers for their applications.

Suggested Reading => Popular SendGrid Competitors

When compared based on pricing, SendGrid provides monthly plans and has a free plan as well. Mailjet also has monthly plans. You can use this service for free, for up to 6000 emails per month. Mandrill provides a monthly plan but it is based on the number of blocks.

Amazon has flexible pricing options. Mailgun pricing policy is based on the number of emails sent per month and the number of validations required. SendGrid, Mailjet, and Mailgun have free plans with a limited number of emails.

Hope you would have got a clear idea about the Top Transactional Email API services through this article!!

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