5 Most Popular Transactional Email Service Providers in 2021

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 emails.

Transactional Email API Service

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.

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Top Transactional Email Service Providers In 2021

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

Comparison of Top Email API Services

Email API Service ToolsUsed ForPriceUsersSupported languages, frameworks, and libraries

SendinBlue Logo
Digital MarketingFree plan: 300 emails/pay & the price starts at $25/month.MarketersEasy integrations with C#, Go, Java, Node JS, PHP, Python, Ruby, Typescript-node.
HubSpot Email Marketing

Hubspot Logo
Marketing emails, bulk email, email newsletter.Free plan: 2,000 emails/month.MarketersTemplates support HTML, CSS and HubL. Easy integration with Node.js, PHP, Ruby and Python.

Transactional and marketing emails.Free plan with 6000 email per month.
Basic plan: Starts at $8. 69 per month
TeamsPHP, Python, Ruby, Java, Node.js, ES2015, Go, C#.

Email Newsletter,
Shipping Notifications,
Promotional Emails, &
Password Resets.
Free plan,
Essentials: Starts at $9.95/month,
Pro: Starts at $79.95 per month,
Premier: Custom.
Developers, Marketers.Frameworks and client libraries. PHP, Python, Ruby, Java, Node.js, Go, C#.

Transactional & bulk emailFree: 10000 emails & 100 validations per month.
Price will increase depending on emails & validations.
DevelopersRails, Python, PHP, Java, Microsoft.Net, Node.js
Amazon SES

Marketing, Notification. & Transactional emailsPrice starts at $0.10.Businesses & DevelopersIntegration with other AWS services.

Data-driven emails, E-commerce, Personalized one-to-one messages. 1-20 blocks: $20 per block.
21-40 blocks: $18 per block.
MailChimp usersPHP, Ruby, Python.

Let’s Explore!!

#1) Sendinblue

Pricing: Sendinblue 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.

SendinBlue Transactional Email Marketing

Sendinblue provides a complete all-in-one digital marketing toolbox. Sendinblue provides the 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 the marketing messages to a targeted audience. Sendinblue will let you choose the setup option from various options such as API, SMTP, Relay, eCommerce plugins, or marketing automation.


  • Sendinblue provides various professionally designed templates.
  • The tool has a drag-and-drop editor to help you design the 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.

#2) HubSpot Email Marketing

HubSpot 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 Email Marketing

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


  • 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.

#3) Mailjet

Mailjet Pricing: 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. The tool will allow you to personalize email templates. You will be able to work as a team on email designing.


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

#4) 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. It offers a mobile app as well so that you can share this single email platform with the team. It extends support through video tutorials, online community, and documentation.


  • 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 many more.

Website: SendGrid

#5) 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. This service will scale as per your needs.


  • 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: Mailgun

#6) 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 for sending 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.


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

Website: Amazon SES

#7) 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.


  • 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: Mandrill


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 the 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!!

=> Contact us to suggest a listing here.