Email Configuration

Overview

BillBuddy uses email notifications to send settlement summaries to group members after expenses are settled. The application uses Web3Forms, a simple email API service, to handle email delivery.

While the package.json includes Nodemailer as a dependency, the current implementation uses Web3Forms for email delivery.

Email Service Setup

Web3Forms Configuration

BillBuddy uses Web3Forms for sending emails. Web3Forms provides a simple API without requiring SMTP configuration.

Getting Started

Visit Web3Forms
Sign up for a free account
Create a new access key from your dashboard
Add the access key to your environment variables

Environment Variable

WEB3FORMS_ACCESS_KEY

string

required

Your Web3Forms access key for sending emails through their API.

.env

WEB3FORMS_ACCESS_KEY=your_web3forms_access_key_here

Email Implementation

The email functionality is implemented in the backend/utils/email.js file:

backend/utils/email.js

const axios = require('axios');

const sendSettlementEmail = async (group, balances) => {
  try {
    const members = group.members.map(member => member.user.email);
    const subject = `Settlement Summary for ${group.name}`;

    // Create email body
    let body = `<h2>Settlement Summary for ${group.name}</h2>`;
    body += '<h3>Final Balances:</h3><ul>';

    // Add balances to email body
    Object.entries(balances).forEach(([userId, balance]) => {
      const member = group.members.find(m => m.user._id.toString() === userId);
      if (member) {
        const name = member.user.name;
        if (balance > 0) {
          body += `<li>${name} is owed Rs. ${balance.toFixed(2)}</li>`;
        } else if (balance < 0) {
          body += `<li>${name} owes Rs. ${Math.abs(balance).toFixed(2)}</li>`;
        } else {
          body += `<li>${name} is settled up</li>`;
        }
      }
    });

    body += '</ul>';
    body += '<p>Thank you for using BillBuddy!</p>';

    // Send email using Web3Forms
    const response = await axios.post('https://api.web3forms.com/submit', {
      access_key: process.env.WEB3FORMS_ACCESS_KEY,
      subject,
      from_name: 'BillBuddy',
      from_email: '[email protected]',
      to: members.join(','),
      body,
      reply_to: '[email protected]'
    });

    if (response.data.success) {
      console.log('Settlement emails sent successfully');
    } else {
      throw new Error('Failed to send settlement emails');
    }
  } catch (error) {
    console.error('Error sending settlement emails:', error);
    throw error;
  }
};

module.exports = {
  sendSettlementEmail
};

Email Parameters

Web3Forms API Parameters

access_key

string

required

Your Web3Forms access key from the environment variables.

subject

string

required

Email subject line. Dynamically generated with the group name.Example: Settlement Summary for Weekend Trip

from_name

string

default:"BillBuddy"

The sender name displayed in the recipient’s inbox.

from_email

string

default:"[email protected]"

The sender email address. This is a display address and doesn’t need to exist.

string

required

Comma-separated list of recipient email addresses. All group members receive the settlement summary.

body

string

required

HTML email body containing the settlement summary with balances for all group members.

reply_to

string

Email address for replies. Set to a no-reply address by default.

Settlement Email Template

The settlement email includes:

Header: Group name in the subject and body
Final Balances: List showing who owes money and who is owed
Footer: Closing message

Email Format

<h2>Settlement Summary for [Group Name]</h2>
<h3>Final Balances:</h3>
<ul>
  <li>[Member Name] is owed Rs. [Amount]</li>
  <li>[Member Name] owes Rs. [Amount]</li>
  <li>[Member Name] is settled up</li>
</ul>
<p>Thank you for using BillBuddy!</p>

Example Email

<h2>Settlement Summary for Weekend Trip</h2>
<h3>Final Balances:</h3>
<ul>
  <li>John Doe is owed Rs. 250.00</li>
  <li>Jane Smith owes Rs. 150.00</li>
  <li>Bob Johnson owes Rs. 100.00</li>
</ul>
<p>Thank you for using BillBuddy!</p>

Triggering Settlement Emails

Emails are automatically sent when a group settlement is processed through the settlements API:

backend/routes/settlements.js

const { sendSettlementEmail } = require('../utils/email');

// After calculating balances and creating settlement
if (sendEmail) {
  await sendSettlementEmail(group, balances);
}

The sendEmail parameter controls whether emails are sent during settlement. This allows flexibility for testing or dry-run settlements.

Usage Example

To send settlement emails programmatically:

const { sendSettlementEmail } = require('./utils/email');

// Assuming you have a group object and balances
const group = await Group.findById(groupId)
  .populate('members.user', 'name email');

const balances = {
  'user_id_1': 250.00,   // User is owed Rs. 250
  'user_id_2': -150.00,  // User owes Rs. 150
  'user_id_3': 0         // User is settled up
};

try {
  await sendSettlementEmail(group, balances);
  console.log('Settlement emails sent successfully');
} catch (error) {
  console.error('Failed to send emails:', error);
}

Error Handling

The email service includes comprehensive error handling:

try {
  const response = await axios.post('https://api.web3forms.com/submit', {...});
  
  if (response.data.success) {
    console.log('Settlement emails sent successfully');
  } else {
    throw new Error('Failed to send settlement emails');
  }
} catch (error) {
  console.error('Error sending settlement emails:', error);
  throw error;
}

Email failures will throw an error and should be caught by the calling function. Consider implementing retry logic for production deployments.

Alternative: Nodemailer Configuration

If you prefer to use Nodemailer instead of Web3Forms, you can configure SMTP settings:

Environment Variables for Nodemailer

.env

EMAIL_HOST=smtp.gmail.com
EMAIL_PORT=587
EMAIL_USER=[email protected]
EMAIL_PASS=your_app_specific_password

Nodemailer Implementation

const nodemailer = require('nodemailer');

// Create transporter
const transporter = nodemailer.createTransport({
  host: process.env.EMAIL_HOST,
  port: process.env.EMAIL_PORT,
  secure: false, // true for 465, false for other ports
  auth: {
    user: process.env.EMAIL_USER,
    pass: process.env.EMAIL_PASS
  }
});

// Send email
const sendEmail = async (options) => {
  const mailOptions = {
    from: `BillBuddy <${process.env.EMAIL_USER}>`,
    to: options.to,
    subject: options.subject,
    html: options.body
  };

  await transporter.sendMail(mailOptions);
};

Gmail Configuration

For Gmail, you need to use an App Password instead of your regular password. Enable 2-factor authentication and generate an app password from your Google Account settings.

Testing Email Functionality

Test Email Sending

Create a test script to verify email configuration:

test-email.js

const { sendSettlementEmail } = require('./utils/email');

// Mock group data
const testGroup = {
  name: 'Test Group',
  members: [
    { user: { email: '[email protected]', name: 'Test User 1', _id: '1' } },
    { user: { email: '[email protected]', name: 'Test User 2', _id: '2' } }
  ]
};

const testBalances = {
  '1': 100,
  '2': -100
};

sendSettlementEmail(testGroup, testBalances)
  .then(() => console.log('Test email sent'))
  .catch((err) => console.error('Test failed:', err));

Run the test:

node test-email.js

Troubleshooting

Email Not Sending

Problem: Emails are not being delivered Solution:

Verify WEB3FORMS_ACCESS_KEY is set correctly
Check the Web3Forms dashboard for usage limits
Ensure recipient email addresses are valid
Check application logs for error messages

Invalid Access Key

Problem: 401 Unauthorized or authentication errors Solution:

Verify the access key in your .env file
Generate a new access key from Web3Forms dashboard
Restart the server after updating the key

Emails Going to Spam

Web3Forms handles email delivery infrastructure, but recipient mail servers may still flag emails as spam.

Tips to improve delivery:

Use a professional sender name
Keep email content clear and concise
Avoid spam trigger words
Consider using a custom domain for from_email

Rate Limiting

Web3Forms has rate limits based on your plan:

Free Plan: 250 emails per month
Paid Plans: Higher limits available

Monitor your email usage to avoid hitting rate limits during high-traffic periods. Consider implementing a queue system for large-scale deployments.

Best Practices

Error Handling: Always wrap email sending in try-catch blocks
Logging: Log email send attempts and failures for debugging
Testing: Test email functionality in development before deploying
Monitoring: Track email delivery success rates
Fallback: Consider implementing a fallback notification method (SMS, in-app notifications)
Templates: Use email templates for consistent formatting
Personalization: Include recipient names and relevant details

Security Considerations

Never expose your Web3Forms access key in client-side code or public repositories.

Store access keys in environment variables only
Rotate access keys periodically
Monitor usage for unusual activity
Validate email addresses before sending
Sanitize user input in email content to prevent injection attacks

Get Started

Core Features

Guides

Configuration

Email Configuration

Overview

Email Service Setup

Web3Forms Configuration

Getting Started

Environment Variable

Email Implementation

Email Parameters

Web3Forms API Parameters

Settlement Email Template

Email Format

Example Email

Triggering Settlement Emails

Usage Example

Error Handling

Alternative: Nodemailer Configuration

Environment Variables for Nodemailer

Nodemailer Implementation

Gmail Configuration

Testing Email Functionality

Test Email Sending

Troubleshooting

Email Not Sending

Invalid Access Key

Emails Going to Spam

Rate Limiting

Best Practices

Security Considerations

Build docs developers (and LLMs) love

Get Started

Core Features

Guides

Configuration

​Overview

​Email Service Setup

​Web3Forms Configuration

​Getting Started

​Environment Variable

​Email Implementation

​Email Parameters

​Web3Forms API Parameters

​Settlement Email Template

​Email Format

​Example Email

​Triggering Settlement Emails

​Usage Example

​Error Handling

​Alternative: Nodemailer Configuration

​Environment Variables for Nodemailer

​Nodemailer Implementation

​Gmail Configuration

​Testing Email Functionality

​Test Email Sending

​Troubleshooting

​Email Not Sending

​Invalid Access Key

​Emails Going to Spam

​Rate Limiting

​Best Practices

​Security Considerations

Build docs developers (and LLMs) love

Overview

Email Service Setup

Web3Forms Configuration

Getting Started

Environment Variable

Email Implementation

Email Parameters

Web3Forms API Parameters

Settlement Email Template

Email Format

Example Email

Triggering Settlement Emails

Usage Example

Error Handling

Alternative: Nodemailer Configuration

Environment Variables for Nodemailer

Nodemailer Implementation

Gmail Configuration

Testing Email Functionality

Test Email Sending

Troubleshooting

Email Not Sending

Invalid Access Key

Emails Going to Spam

Rate Limiting

Best Practices

Security Considerations