Best Transactional Email API Service for Developers in US

Deliver transactional emails effortlessly with high open rates using our robust and developer-friendly APIs.
Offer your customers a flawless experience by consistently updating them with essential information across the USA.

Send critical information using our transactional email service

Transactional emails are personalized messages, intended to inform customers about essential things like order updates, OTPs, order details, and more.

Customize, revamp and send crucial
transactional emails to your customers in the US

Account creation | Password reset | Purchase receipt | Account notification and more..

Ready for use
in under 5 minutes

Our Email API service is for the developers by the developers. You can set it up in minutes.
Leverage reporting, tracking, email analysis, and A/B testing while sending transactional emails using our email API.
Send targeted, personalized messages and emails in the US with a 99.99% accuracy and uptime SLA.

Suppression Management Made Easy

You can easily manage opt-out and opt-in contacts and deliver mails automatically. Use webhooks in our transactional email service and automate the entire opt-out collection list to send emails in real-time.
Opt-out collection automation is not limited to emails. With MSG91, you can also automate opt-out collection for SMS.

Get emails in JSON format

Use JSON to send transactional emails faster via webhooks. Receive each email you send in the JSON format at your server. You can forward the email to MSG91’s unique ID or set up an MX record, and we’ll send you the email as we receive them.

Realtime Notifications via Webhooks

Stay updated with the real-time information on your transactional emails via webhooks. MSG91 webhooks send notifications to your apps regarding crucial events like deliveries, open rates, spam complaints, and bounces.

Customize and Deliver Transaction Emails

Use our entirely customizable transactional email service and deliver target emails like never before.

Why is MSG91 Best for
Sending Transactional Emails in the USA?

Transactional Email to customers on time, every time.


Pay Only for what You use



Custom Emails

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Common features for all plans


Transactional emails are sent to facilitate a consented transaction between the sender and the receiver, for example, the purchase of a product. Transactional emails are personalized and data-driven emails that are informational and non-marketed in nature. Transactional emails normally consist of information that a recipient wants or needs and consequently have very high opening (click) rates.

Common reasons to send transactional email to recipients include account opening emails, other device log-in flags, OTP verification, password resets, order receipts, account notifications, admission status, flight updates, and social media updates like upload and follower notifications. The information covered in these emails helps your customers to take further coherent actions wherever necessary.  

After creating your account with MSG91, To get started with emails, get your domain added and fully configured. Then Set up SMTP or integrate with API to start sending transactional emails. Get API for Transactional email in the doc

A transactional email is an automatically generated email exchanged between a sender and a recipient. 

Transactional emails are non-marketing informational messages that organizations and institutions have to send in order to validate a transaction or provide a product or service, as required by the client. Due to the mission-critical nature of transactional emails, businesses do not need to take consent from the customers beforehand to send these emails. For this reason, businesses don't need to take express consent from the recipient to send transactional emails. The updates and information are sent directly to the registered email address provided while logging in.

Once you have created the basic format of your transactional emails, these are auto-generated through programming and sent to the right customer. Use the following tips to create your email using MSG91 Email API for transactional email services.


  • Consider what the user may be doing right before your email notification appears in their inbox.
  • Focus on positioning your update in such a way that it helps the user by making their job easier, for instance sending easy to follow instructions and steps or links that auto-verify on once click.
  • Get to the information straight away. Make sure that the main update is in the subject line as well so that it is the first thing a reader sees in the email and knows exactly what your prompt is regarding.
  • Make use of templates and prompts for guidance.

A transactional email service is a service provided by organizations that enable businesses to send strategic transactional emails to their customers with lesser manual effort. MSG91 has robust developer-friendly APIs which help businesses create, customize and send transactional emails through proprietary transactional email software.
Within a few easy steps, you can keep your customers updated with their order details, booking status, login prompts, and other essential information that may or may not require an action from them.

A transactional email API (application programming interface) gives applications access to functionality available in an email platform. By using a robust transactional email API like that of MSG91, you can easily generate, optimize and send data-driven and personalized transactional emails. You can also enable access to A/B testing, scheduling, email analytics and tracking the status of the transactional emails sent to the recipient.