Transactional email API service for developers

MailerSend’s powerful RESTful API service is built with you in mind. Start integrating email sending quickly with our official libraries, and authenticate API requests with tokens.

Quick and easy email API integration

MailerSend fits right into your stack with libraries for your favorite programming languages, including PHP, Node.js, Golang, Python, Ruby, Java and Laravel, plus comprehensive API documentation.
Read our API docs
curl -X POST \
https://api.mailersend.com/v1/email \
    -H 'Content-Type: application/json' \
    -H 'X-Requested-With: XMLHttpRequest' \
    -H 'Authorization: Bearer {place your token here without brackets}' \
    -d '{
        "from": {
            "email": "your@email.com"
            "to": [
            "email": "your@client.com"
        "subject": "Hello from MailerSend!",
        "text": "Greetings from the team, you got this message through MailerSend.",
        "html": "

Greetings from the team, you got this message through MailerSend.

" }'
use MailerSend\MailerSend;
use MailerSend\Helpers\Builder\Recipient;
use MailerSend\Helpers\Builder\EmailParams;

$mailersend = new MailerSend(['api_key' => 'key']);

$recipients = [
new Recipient('your@client.com', 'Your Client'),

$emailParams = (new EmailParams())
->setFromName('Your Name')

Greetings from the team, you got this message through MailerSend.

') ->setText('Greetings from the team, you got this message through MailerSend.'); $mailersend->email->send($emailParams);
const Recipient = require("mailersend").Recipient;
const EmailParams = require("mailersend").EmailParams;
const MailerSend = require("mailersend");

const mailersend = new MailerSend({
    api_key: "key",

const recipients = [new Recipient("your@client.com", "Your Client")];

const emailParams = new EmailParams()
    .setFromName("Your Name")

Greetings from the team, you got this message through MailerSend.

") .setText("Greetings from the team, you got this message through MailerSend."); mailersend.send(emailParams);
package main

import (


var APIKey string = "Api Key Here"

func main() {
    ms := mailersend.NewMailersend(APIKey)

    ctx := context.Background()
    ctx, cancel := context.WithTimeout(ctx, 5*time.Second)
    defer cancel()

    subject := "Subject"
    text := "Greetings from the team, you got this message through MailerSend."
    html := "

Greetings from the team, you got this message through MailerSend.

" from := mailersend.From{ Name: "Your Name", Email: "your@email.com", } recipients := []mailersend.Recipient{ { Name: "Your Client", Email: "your@client.com", }, } variables := []mailersend.Variables{ { Email: "your@client.com", Substitutions: []mailersend.Substitution{ { Var: "foo", Value: "bar", }, }, }, } tags := []string{"foo", "bar"} message := ms.NewMessage() message.SetFrom(from) message.SetRecipients(recipients) message.SetSubject(subject) message.SetHTML(html) message.SetText(text) message.SetSubstitutions(variables) message.SetTags(tags) res, _ := ms.Send(ctx, message) fmt.Printf(res.Header.Get("X-Message-Id")) }
from mailersend import emails

mailer = emails.NewEmail()

mail_body = {}

mail_from = {
    "name": "Your Name",
    "email": "your@domain.com",

recipients = [
        "name": "Your Client",
        "email": "your@client.com",

mailer.set_mail_from(mail_from, mail_body)
mailer.set_mail_to(recipients, mail_body)
mailer.set_subject("Hello!", mail_body)

Greetings from the team, you got this message through MailerSend.

", mail_body) mailer.set_plaintext_content("Greetings from the team, you got this message through MailerSend.", mail_body) mailer.send(mail_body)
require "mailersend-ruby"

# Intialize the email class
ms_email = Mailersend::Email.new

# Add parameters
ms_email.add_recipients("email" => "your@client.com", "name" => "Your Client")
ms_email.add_recipients("email" => "your@client.com", "name" => "Your Client")
ms_email.add_from("email" => "your@domain.com", "name" => "Your Name")
ms_email.add_text("Greetings from the team, you got this message through MailerSend.")
ms_email.add_html("Greetings from the team, you got this message through MailerSend.")

# Send the email

Send emails from your apps

Start sending emails with MailerSend’s email API service in just a few minutes and get access to advanced functionality like personalization, bulk sending, attachments and more.


Proven experience that delivers

MailerSend is backed by a decade of email delivery experience. We built  a powerful and secure infrastructure that empowers you to send transactional emails knowing that they will reach the inbox.


Let your team handle the rest

Allow your whole team to contribute by granting specific permissions or assigning roles so they can take care of template design. Add up to 20 users on Premium plans or unlimited on Enterprise.


Three email builders for all skillsets

Create emails in minutes with pre-made content blocks in the intuitive drag & drop email editor or opt for simplicity with the rich-text builder. Advanced users can code templates from scratch with the HTML email builder.


Allow users to interact with inbound routing

Easy to configure inbound routing enables MailerSend to parse incoming emails to your app, so users can effortlessly post replies, comments and emails.


Easily connect other web apps with MailerSend so they seamlessly work together to share information, automate workflows and enhance your customer experience.
Select webhook activities in MailerSend

Get real-time notifications with webhooks

Optimize users’ workflows with instant notifications about transactional email events via webhooks. Get updates about email delivery, spam complaints, bounces and more without constantly polling the API.


Safeguard your sending domain

Protect your sender reputation with inbox providers using our SPF, DKIM and DMARC security protocols. Authenticate your email content to improve your email deliverability and keep out of the spam folder.


Protect your sender reputation with email verification

Use advanced email verification and the email verification API to identify and remove invalid emails from your recipient list before they harm your sender reputation and deliverability.


Effortlessly monitor performance

Check the dashboard for an overview of your most important performance metrics or dive deep into custom reports in the activity and analytics pages. Keep track of email performance on the go with the MailerSend iOS app.

How developers use MailerSend’s email API


Send order confirmations, shipping notifications, cart abandonment emails, receipts and more.

Learn more

Send password resets, account verification emails, 2-factor authentication, and security alerts.

Learn more
Social networking

Deliver notifications, account alerts, and password resets and use inbound routing for message replies.


Update jobseekers with job alerts, updates on their applications and conversations with recruiters.


Provide updates about courses, assignments and examination results to students.

Financial services

Send alerts about transactions, security alerts, monthly statements and more to customers.

Learn more
Customer support

Provide automated responses to queries, ticket updates, and surveys and allow customers to respond with inbound routing

Booking and reservations

Send confirmation emails for travel, accommodation and reservations and send e-tickets for events and more.

Here’s what developers say about MailerSend

Amazing product and support

"MailerSend is extremely easy to use and super fast to set up. I was able to send the first email via the API in minutes. What's really worth mentioning is the outstanding customer support."

Tobias R.

Easy to send via API

"It is quite easy to create new templates and send them through the API. Up until now, we didn't have any problems with receiving emails. Plus, the customer support is great!"

Markus G.

For developers and designers

"Super easy to use API for devs. Easy to use mail templating for designers. Developers don't need to do design, and designers don't need to code as well. It's awesome."

Raphael A.

Frequently asked questions

What is MailerSend?

MailerSend is a transactional messaging service provider that offers a powerful email API, built so that developers can integrate transactional email sending into their stack quickly and easily.

Do you also offer an SMS API?

Yes! Our easy-to-use SMS API allows you to send high-volume, toll-free SMS within North America. Availability in more regions is on the way.

Can I send email marketing campaigns through MailerSend?

While you could send marketing emails, the MailerSend platform is built for transactional emailing. To get the best performance and deliverability for both marketing and transactional email campaigns, we recommend keeping them separate. We offer SSO capability with MailerLite, so you can connect and use a single account for both your marketing emails and transactional emails while still keeping them separate.

Can I get a dedicated IP address?

Dedicated IPs are available for high-volume senders. Get in touch with us to find out if a dedicated IP is right for you.

How does MailerSend pricing work?

Pricing is based on the number of emails you send. Our free plan includes 3,000 emails, with additional emails charged on a pay as you go basis at a rate of $1.00/1,000. Our cost-effective Premium plan is available for up to 2,500,000 emails/month, with additional emails charged at decremental rates starting at $0.90/1,000. If you need more than 2,500,000 emails, you can talk to us about a custom Enterprise plan.

Can I send emails via SMTP (Simple Mail Transfer Protocol)?

Yes, we have a plugin available if you wish to send emails through SMTP, although we recommend using the email API for more advanced functionality.

Do you provide email templates?

MailerSend has a rich gallery of free, responsive transactional email templates that have been professionally designed for many use cases. You can simply choose a template and make it your own.

Does MailerSend validate email addresses?

We’re working on an email validation feature, which will be available soon, so that you can verify individual email addresses or your entire list in bulk. 

More features to explore

MailerSend is packed full of features that help you save time and grow your business.

Integrate emails in your stack now

Use our email API to start sending emails from your apps. Get started with 3,000 free emails per month! Includes 24/7 help from a friendly and dedicated support team.

Step 1

Sign up for a free account

Step 2

Send an email from the trial domain

Step 3

Try out the features & check your activity