As a developer, email sending is a recurent task across the projects.

Most part of time, you have to deal with open source libraries, to switch from a library to another accross the projects, with some particular implementations and / or behaviors.

As well, you can have a different need inside a same project just regarding the use case.

For example, you can still need to send an email to a developer when a particular event is fired, or send a transactionnal email to say welcome to a new user.

In the first case, a simple SMTP server can do the job internally.

In the second case, it's more efficient to rely to a web API, able to manage statistics, bouncing, DKIM, templating, ...

As well, you can need to deal with different providers at the same time. During a migration, for example.

Some months ago, I was wondering how to provide something flexible and consistent to deal with this kind of repetitive issue.

And I did it myself, because it was quite fun. 😎

All the cases described above - and some others - are covered by a light NPM package.

The main features are:

• Configuration based
• Agnostic appoach: same input, same output for all configurations
• Formalized transactions conventions
• Unlimited number of transporters inside the same project
• Support of different sending modes (SMTP and web API)
• Embeded view engine, stream or web API templates

There is Cliam, an agnostic and very flexible tool to deal with transactional email sending.

> npm i cliam --save

> touch .cliamrc.js

module.exports = {
  "sandbox": true,
  "transporters": [
    {
      "id": "unique-transporter-key",
      "auth": {
        "username": process

Currently, following web api providers are supported: Mailgun, Mailjet, Brevo, Sendinblue, Sendgrid, Mandrill, Sparkpost, Mailsender and Postmark. Amazon SES and a lot of others should be integrated soon, but I prefer take the focus on some new features and to push more robustness before to embedd too much transporters.

Have a good dev, enjoy and feel free to use and to share 🚀