Transactional email service that delivers

MailerSend is a new kind of transactional email service designed for collaboration across entire teams. Intuitively-designed tools allow anyone to contribute, while an advanced infrastructure lets you scale fast.

What are transactional emails?

Transactional emails are automated messages triggered by the specific actions of a recipient on your app or website. Common types of transactional emails include password resets, account creation, notification emails and social media updates.


Business online is driven by automated email messages. Transactional messages like password reset emails, account notification emails, two-factor authentication emails and order confirmation emails are automatically sent along the customer journey.

Get started with MailerSend’s powerful API or SMTP relay

Our robust RESTful API service is built so that developers can integrate transactional email quickly with their favorite language while the SMTP plugin provides a no-code solution for secure, reliable email sending.
Check out our API documentation
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 transactional emails with confidence

MailerSend is backed by a decade of email delivery experience as an award-winning email service provider. Get expert advice on email deliverability and learn how to increase your open rates, avoid the spam folder and much more.


Improve your deliverability with email verification

Maintain a good sender reputation and keep sending costs down with the inbuilt email verification tool. Remove invalid email addresses and only send transactional emails to real recipients.


Personalize emails on a mass scale

Build stronger customer relationships and enjoy higher engagement by tailoring your email template to individual recipients. Conditional personalization of email subject lines and content makes people feel that the email was written for them.

Integrate bulk email sending

Optimize your sendings with the bulk email endpoint. Schedule multiple emails for a later time to avoid peak sending times, sync delivery with an event or bypass rate limits by sending thousands of emails in a single request.


Drag & drop to design professional emails

Anyone in the team can design beautiful, responsive templates with no need for coding. Simply drag and drop the content blocks and customize as needed for professional-looking and engaging emails.


Rich library of templates at your fingertips

Choose from our collection of natively responsive transactional email templates, professionally designed to fit a range of use cases. Select your preferred template and edit it with your brand design and content to make it your own.


Collaborate as a team

Developers can focus on what they do best while the rest of the team can easily create templates, manage domain settings and track user behavior through MailerSend’s analytics. Discover the benefits of a team-friendly transactional email provider!


Gain real-time insights into emails

MailerSend’s analytics tool contains the information that you need to optimize your emails. View detailed email activity to learn more about your recipients, track their interactions and review triggered messages from event webhooks.

Frequently Asked Questions

What is an example of a transactional email?

A transactional email is any type of email that is triggered by the action of a user or customer. Examples of transactional emails include password reset emails, account creation emails, account notification emails, two-factor authentication emails, order confirmation emails, shipping notification emails and appointment reminded emails.

What’s the difference between transactional and marketing emails?

Marketing emails are scheduled by the sender and are sent to subscribers who have opted-in to receive newsletters and other promotional content. Transactional emails are triggered by the recipient via an action on your app or website, for example, by making a purchase. You do not need recipients to opt-in to send them transactional emails, as their purpose is to deliver important information about their account, purchase or activity. Continue reading about the difference between transactional and marketing emails.

Why choose MailerSend as your transactional email provider?

MailerSend is a powerful yet easy-to-work-with transactional email service, backed by deliverability experts with over 10 years of experience in the email industry. We also provide award-winning support, so you'll never be left in the dark about any issues or questions you have about your account. What's more, MailerSend is one of the most advanced and comprehensive transactional email solutions available. Sign up for free.

What are the benefits of a transactional email service?

Transactional email is all about speedy delivery. These important messages need to make it to customers' inboxes in a timely manner, and it takes a robust sending infrastructure as well as a strong sender reputation to make that happen. Transactional email services are built to deal with large volumes of email, and are optimized to ensure the highest level of deliverability. What's more, a transactional email service also provides the tools needed to develop a winning transactional email strategy and to easily manage recipients.

Is MailerSend transactional email service free?

MailerSend offers a generous free tier which provides 3,000 emails per month. Additional emails are purchased on a pay-as-you-go basis, or users can choose to upgrade to a Premium plan starting at $30 per month for 50,000 emails, which is more cost-effective and includes advanced features. Visit to our pricing page for more details.

More features to explore

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

Start collaborating on transactional emails now

Try MailerSend for free for up to 100 emails with a trial domain. Add your own domain to get 3,000 emails/month free and start sending.