Reusable Node Code Modules, Part 6 - Notifications - Email

Keeping Users Informed: Implementing Reusable Email Notification Modules

Email notifications are crucial for user communication, including account verification, password resets, and general updates. Implementing a reusable email notification module ensures consistent email handling across projects. This guide covers how to structure reusable email notification modules in Node.js using Express, manage email sending efficiently, and integrate common libraries.

Common Libraries and Tools

1. Nodemailer

Nodemailer is a popular module for sending emails in Node.js.

Key Features

• SMTP Support: Supports sending emails via SMTP

• OAuth2: Supports OAuth2 for secure authentication

• Attachments: Allows sending emails with attachments

• Templating: Supports various templating engines for email content

2. SendGrid

SendGrid is a cloud-based email service that provides reliable email delivery

Key Features

• Email Delivery: Reliable email delivery with high deliverability rates

• Templates: Supports dynamic email templates

• Analytics: Provides email analytics and tracking

• API Integration: Easy integration with a RESTful API

3. Mailgun

Mailgun is an email automation service for sending, receiving, and tracking emails

Key Features

• Email Delivery: High deliverability with advanced email routing

• Validation: Email validation to ensure accurate email addresses

• Tracking: Detailed email tracking and analytics

• API Integration: Simple and flexible API for integration

4. Amazon SES (Simple Email Service)

Amazon SES is a cost-effective, scalable email service for businesses

Key Features

• Scalability: Easily scales to handle large volumes of emails

• Cost-Effective: Competitive pricing for high-volume email sending

• Security: Supports DKIM, SPF, and DMARC for email security

• Integration with AWS: Seamlessly integrates with other AWS services

Comparison

• Nodemailer: Best for simple email sending with SMTP support and templating.

• SendGrid: Ideal for reliable email delivery with dynamic templates and analytics.

• Mailgun: Suitable for advanced email routing, validation, and tracking.

• Amazon SES: Best for scalable, cost-effective email sending with strong security features.

Examples and Wrapper Class

Example 1: Nodemailer

Setup:

$ npm install nodemailer

Configuration:

import nodemailer from 'nodemailer';

const transporter = nodemailer.createTransport({
  service: 'gmail',
  auth: {
    user: 'your-email@gmail.com',
    pass: 'your-email-password'
  }
});

const sendEmail = async (to, subject, text) => {
  const mailOptions = {
    from: 'your-email@gmail.com',
    to,
    subject,
    text
  };

  try {
    await transporter.sendMail(mailOptions);
    console.log('Email sent successfully');
  } catch (error) {
    console.error('Error sending email:', error);
  }
};

export default sendEmail;

Wrapper Class:

class EmailClient {
  constructor() {
    this.transporter = transporter;
  }

  async sendEmail(to, subject, text) {
    const mailOptions = {
      from: 'your-email@gmail.com',
      to,
      subject,
      text
    };

    try {
      await this.transporter.sendMail(mailOptions);
      console.log('Email sent successfully');
    } catch (error) {
      console.error('Error sending email:', error);
    }
  }
}

export default new EmailClient();

Example 2: SendGrid

Setup:

$ npm install @sendgrid/mail

Configuration:

import sgMail from '@sendgrid/mail';

sgMail.setApiKey('your-sendgrid-api-key');

const sendEmail = async (to, subject, text) => {
  const msg = {
    to,
    from: 'your-email@example.com',
    subject,
    text
  };

  try {
    await sgMail.send(msg);
    console.log('Email sent successfully');
  } catch (error) {
    console.error('Error sending email:', error);
  }
};

export default sendEmail;

Wrapper Class:

class SendGridClient {
  constructor() {
    sgMail.setApiKey('your-sendgrid-api-key');
  }

  async sendEmail(to, subject, text) {
    const msg = {
      to,
      from: 'your-email@example.com',
      subject,
      text
    };

    try {
      await sgMail.send(msg);
      console.log('Email sent successfully');
    } catch (error) {
      console.error('Error sending email:', error);
    }
  }
}

export default new SendGridClient();

Example 3: Mailgun

Setup:

$ npm install mailgun-js

Configuration:

import mailgun from 'mailgun-js';

const mg = mailgun({ apiKey: 'your-mailgun-api-key', domain: 'your-mailgun-domain' });

const sendEmail = async (to, subject, text) => {
  const data = {
    from: 'your-email@example.com',
    to,
    subject,
    text
  };

  try {
    await mg.messages().send(data);
    console.log('Email sent successfully');
  } catch (error) {
    console.error('Error sending email:', error);
  }
};

export default sendEmail;

Wrapper Class:

class MailgunClient {
  constructor() {
    this.mg = mailgun({ apiKey: 'your-mailgun-api-key', domain: 'your-mailgun-domain' });
  }

  async sendEmail(to, subject, text) {
    const data = {
      from: 'your-email@example.com',
      to,
      subject,
      text
    };

    try {
      await this.mg.messages().send(data);
      console.log('Email sent successfully');
    } catch (error) {
      console.error('Error sending email:', error);
    }
  }
}

export default new MailgunClient();

Example 4: Amazon SES

Setup:

$ npm install aws-sdk

Configuration:

import AWS from 'aws-sdk';

AWS.config.update({
  accessKeyId: 'your-access-key-id',
  secretAccessKey: 'your-secret-access-key',
  region: 'your-region'
});

const ses = new AWS.SES({ apiVersion: '2010-12-01' });

const sendEmail = async (to, subject, text) => {
  const params = {
    Destination: {
      ToAddresses: [to]
    },
    Message: {
      Body: {
        Text: { Data: text }
      },
      Subject: { Data: subject }
    },
    Source: 'your-email@example.com'
  };

  try {
    await ses.sendEmail(params).promise();
    console.log('Email sent successfully');
  } catch (error) {
    console.error('Error sending email:', error);
  }
};

export default sendEmail;

Wrapper Class:

class SESClient {
  constructor() {
    AWS.config.update({
      accessKeyId: 'your-access-key-id',
      secretAccessKey: 'your-secret-access-key',
      region: 'your-region'
    });

    this.ses = new AWS.SES({ apiVersion: '2010-12-01' });
  }

  async sendEmail(to, subject, text) {
    const params = {
      Destination: {
        ToAddresses: [to]
      },
      Message: {
        Body: {
          Text: { Data: text }
        },
        Subject: { Data: subject }
      },
      Source: 'your-email@example.com'
    };

    try {
      await this.ses.sendEmail(params).promise();
      console.log('Email sent successfully');
    } catch (error) {
      console.error('Error sending email:', error);
    }
  }
}

export default new SESClient();