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Leonidas Costas
Leonidas Costas

Posted on • Updated on • Originally published at

Automatic Mail Campaign Creation with Mailjet

Hi Sparta!

In this article I will share with you how to create marketing campaigns, newsletters... automatically in your NestJS backend 💌

The full source code and the documentation is available on GitHub or on FMP 🙂

This newsletter / marketing campaign module will be added top of the React/Node/MySQL starter. This starter has already been presented to you in this article.

How does it work ?

We'll use Mailjet's API in order to:

  • Create a "Contact" for every user of your app
  • Add them to an already existing ContactList created on Mailjet side
  • Update their metadatas (whether or not their profil are verified)
  • Create campaign draft
  • Send a test mail to a dev adress in order to preview the futur campaign that will be sent
  • Schedule the campaign for all user's missing the verification of their profil

High picture of the workflow

  • A user sign up to your web app.
  • A user is created in databse and on Mailjet side as a "Contact" (name, email, hasVerifiedProfil)
  • Every day a 6pm05 we generate automatically a campaign draft to ask for the verification of their account (for user's who haven't done it before).
  • The campaign is scheduled for 6pm35.
  • The draft is sent to you, in order to verify their is no issue in content that will be sent to your user. If an issue occurs, you can delete the scheduled campaign in your Mailjet account. You could then retrigger the campaign generation with Postman once the content is corrected.

Step by step guide

  • 1 - Account creation

Create a MailJet account here.

  • Step 2 - Install mailjet dependency

Install the node-mailjet dependency in the backend directory of your project.

npm install node-mailjet@3.3.1
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  • Step 3 - Mailjet credentials

Add your mailjet API credentials in your environments files (DEV, STAGING & PROD) found in the backend/src/environments directory.

export const environment = {
  mailjet: {
    apiKey: '%YOUR_API_KEY%',
    secretKey: '%YOUR_SECRET_KEY%',
    contactListID: TODO_LATER,
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Your credentials can be found using this link.

  • Step 4 - Contact lists config Create two contact lists in your Mailjet account. One will be used in dev env mylist_dev and the other one will be used for production mylist_prod.

To do so, in your Mailjet account : "Contact" > "Contact List" > "Create a contact a list".

Properties of your user should contains at least "email" (string), "name" (string) and hasVerified (boolean).

Once created, the the contactListID in backend/src/environments in the mailjet config.

  • Step 5 - Segment config
    A segment is a subset of contacts from a contact list that matchs your condition on the metadatas of the contact.
    In our case, we'll create a segment "verification_not_done" that will contains all contact from mylist_prod having hasVerified properties equal to false.

  • Step 6 - Mail template config
    Create your campaign template with your Mailjet account : "Models" > "My Marketing Models" > "Create a new model".
    Once created, copy the ID of the template and set it as value of ACCOUNT_VERIFICATION_TEMPLATE in campaign-templates.enum.ts.

Step 7 - Back

Add folder backend/campaign in your backend/src/api.
Don't forget to add CampaignModule in the imports of the app.module.

Add folder backend/mailer in your backend/src/shared.
Don't forget to add MailerModule in the imports of the app.module.

Step 8 - Contact creation on sign up

When your user sign up, you should create a contact on mailjet side.

To do so, in file backend/src/api/auth.controller.ts add:

import { MailerService } from '../../shared/mailer/mailer.service';


    async signUp(@Body() createUserDto: CreateUserDto): Promise<{ success: boolean, token?: string, id?: number }> {


        const mailjetContact = await this.mailService.createContact(user);

        if (mailjetContact.body.Data[0].ID) {
            console.log("Mailjet contactID", mailjetContact.body.Data[0].ID);
            await this.mailService.addContactToContactList(mailjetContact.body.Data[0].ID);

            await this.usersService.update(user, { contactId: mailjetContact.body.Data[0].ID });
            await this.mailService.updateDefaultContactMetadatas(mailjetContact.body.Data[0].ID, createUserDto.firstname);
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You can then verify in your contactList on your mailjet acccount the new user created on sign up.

Step 9 - Automatic campaign creation

Every friday at 6pm05, your campaign will be created, and scheduled at 6pm35 on all users that did not verify their account.

    // Every friday at 6pm05
    @Cron('0 5 18 * * 5', {
        name: 'sendMarketingCampaignVerifyAccount',
        timeZone: 'Europe/Paris',
    async sendMarketingCampaignVerifyAccount() {
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To make the NestJS cron work, please install following dependencies:

    npm install --save @nestjs/schedule
    npm install --save-dev @types/cron
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To avoid any issue being categorized as "SPAM" you should configure the SPF and DKIM configuration for your sending mail address and your domain : Mailjet profil > "Preferences" > "Domains" > "DKIM/SPF authentication".


I hope this module will help you ! Do not hesitate to pin and star on GitHub if you appreciated the article ❤️


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