​
Overview

The Mailer package is a utility designed to facilitate the process of generating email templates. This package provides a way to style, template, and generate HTML for sending emails using the React Email library

​
Template System

The template system is key to the functionality of the Mailer package. Each template corresponds to a different type of email that can be sent. The specific variables available for substitution in a template depend on the template itself. The Template type should be used to reference the available templates. For example, to reference to verify email template, you would use Template.VERIFY_EMAIL.

​
Adding new Template

All development takes place in the package turborepo packages/mailer. The preview of emails is launched automatically when you launch the application using turborepo or Docker, the application will be available on port 4000.
  1. Create a new template in the emails folder.
  2. Export your component and props interface from the file.
my-app/packages/mailer/emails/verify-email.tsx
import React, { FC } from 'react';
import { Text } from '@react-email/components';

import Layout from './_layout';
import Button from './components/button';

export interface VerifyEmailProps {
  firstName: string;
  href: string;
}

export const VerifyEmail:FC<VerifyEmailProps> = ({
  firstName = 'John',
  href = 'https://ship.paralect.com',
}) => (
  <Layout previewText="Welcome on board the Ship!">
    <Text>
      Dear
      {' '}
      {firstName}
      ,
    </Text>

    <Text>
      Welcome to Ship! We are excited to have you on board.
    </Text>

    <Text>
      Before we get started, we just need to verify your email address.
      This is to ensure that you have access to all our features and so we can send you important account notifications.
    </Text>

    <Text>
      Please verify your account by clicking the button below:
    </Text>

    <Button href={href}>
      Verify email
    </Button>
  </Layout>
);

export default VerifyEmail;
  1. Navigate to src/template.ts file, import your component and props interface.
  2. Add your template to the Template enum, EmailComponent object and TemplateProps type.
my-app/packages/mailer/src/template.ts
import { ResetPassword, ResetPasswordProps } from 'emails/reset-password';
import { SignUpWelcome, SignUpWelcomeProps } from 'emails/sign-up-welcome';
import { VerifyEmail, VerifyEmailProps } from 'emails/verify-email';

export enum Template {
  RESET_PASSWORD,
  SIGN_UP_WELCOME,
  VERIFY_EMAIL,
}

export const EmailComponent = {
  [Template.RESET_PASSWORD]: ResetPassword,
  [Template.SIGN_UP_WELCOME]: SignUpWelcome,
  [Template.VERIFY_EMAIL]: VerifyEmail,
};

export type TemplateProps = {
  [Template.RESET_PASSWORD]: ResetPasswordProps;
  [Template.SIGN_UP_WELCOME]: SignUpWelcomeProps;
  [Template.VERIFY_EMAIL]: VerifyEmailProps;
};
When you change the email template, you need to rebuild the API to see the changes when sending emails.

​
Usage in API

​
Importing

To use the Mailer package within the API, the necessary services and types need to be imported: 
import { Template } from 'types';
import { emailService } from 'services';

​
Sending an Email

To send an email, the sendTemplate function from the emailService is used. This function accepts an object with properties specifying the recipient, subject line, template to be used, and an object with parameters to be filled into the template: 
await emailService.sendTemplate<Template.VERIFY_EMAIL>({
    to: user.email,
    subject: 'Please Confirm Your Email Address for Ship',
    template: Template.VERIFY_EMAIL,
    params: {
      firstName: user.firstName,
      href: `${config.API_URL}/account/verify-email?token=${signupToken}`,
    },
});
In this example, a password reset email is dispatched. The VERIFY_EMAIL template is used, and the user’s first name and the reset password URL are passed as parameters to be substituted into the template.