## SMTP Email Integration Guide This guide explains how to set up email sending using Gmail SMTP. ### Prerequisites - Gmail account - Application-specific password enabled ### Step 1: Enable 2-Factor Authentication on Gmail 1. Go to: https://myaccount.google.com/security 2. Look for "2-Step Verification" 3. Follow the steps to enable 2FA ### Step 2: Create App Password 1. Go to: https://myaccount.google.com/apppasswords 2. Select: - Mail - Windows Computer (or your OS) 3. Google will generate a 16-character password 4. Copy this password (you'll need it for .env) ### Step 3: Get SMTP Credentials **For Gmail:** - SMTP Server: smtp.gmail.com - Port: 587 (TLS) or 465 (SSL) - Username: your-email@gmail.com - Password: Your App Password (from Step 2) **For Other Email Providers:** **Microsoft Outlook:** - SMTP: smtp.office365.com - Port: 587 - Username: your-email@outlook.com - Password: Your account password **SendGrid (Recommended for Production):** - SMTP: smtp.sendgrid.net - Port: 587 - Username: apikey - Password: Your SendGrid API key ### Step 4: Configure .env In `backend/.env`, add: ```env # Gmail Example SMTP_USER=your-email@gmail.com SMTP_PASSWORD=xxxx xxxx xxxx xxxx SMTP_FROM=Trust Tax Advisor ``` ### Step 5: Test Email Sending ```javascript import { sendEmail } from './config/email.js'; const result = await sendEmail( 'recipient@example.com', 'Test Subject', '

Hello!

This is a test email.

' ); console.log(result); // { success: true, messageId: '...' } ``` ### Email Templates #### OTP Email Template ```html

Your OTP Code

Your OTP is: 123456

Valid for 10 minutes.

If you didn't request this, please ignore.

``` #### Order Confirmation Email Template ```html

Order Confirmation

Your order has been received!

Order ID: #12345

Amount: ₹5000

Status: Processing

We'll send you updates via email and WhatsApp.

``` #### Commission Notification Email ```html

Commission Earned

A new commission has been added to your account!

Order: #12345

Amount: ₹2500

Status: Pending

``` ### Integration Examples **Backend - Send OTP via Email** ```javascript async sendOtpEmail(email, otp) { const htmlContent = `

Your OTP is: ${otp}

Valid for 10 minutes

`; return await sendEmail(email, 'OTP - Trust Tax Advisor', htmlContent); } ``` **Backend - Send Order Notification** ```javascript async notifyOrderCreated(clientEmail, order) { const htmlContent = `

Order #${order.id} Created

Amount: ₹${order.amount}

Service: ${order.service_name}

`; return await sendEmail(clientEmail, 'Order Confirmation', htmlContent); } ``` **Backend - Notify Connector of Commission** ```javascript async notifyCommission(connectorEmail, commission) { const htmlContent = `

Commission Earned!

Amount: ₹${commission.amount}

Order: #${commission.order_id}

Status: ${commission.status}

`; return await sendEmail(connectorEmail, 'New Commission', htmlContent); } ``` ### Bulk Email Tips For sending emails to multiple recipients: ```javascript async sendBulkEmails(recipients, subject, htmlContent) { // Add delay to avoid rate limiting for (const email of recipients) { await sendEmail(email, subject, htmlContent); await new Promise(resolve => setTimeout(resolve, 500)); // 500ms delay } } ``` ### Production Best Practices 1. **Use SendGrid or AWS SES** - Better deliverability - Better reporting - Scaled for high volume 2. **Email Queue System** - Use Bull/Kue for email jobs - Retry failed emails - Monitor delivery status 3. **Track Email Opens** - Add tracking pixels - Monitor click-throughs - Improve templates based on analytics 4. **SPF/DKIM Records** - Add SPF record to DNS - Add DKIM signatures - Improve email authentication ### Troubleshooting **"Invalid login credentials" error** - Verify Gmail has 2FA enabled - Check App Password is correct - Don't use regular Gmail password **"SMTP connection failed"** - Check internet connection - Verify SMTP server address - Try different port (587 vs 465) - Check firewall rules **Emails going to Spam** - Add SPF record: `v=spf1 include:gmail.com ~all` - Add DKIM signature - Use branded email address - Test with MXToolbox **"Too many emails" rate limit** - Gmail: 30 emails per second per account - Add delays between emails - Use queue system ### Testing Checklist - [ ] 2-Factor Authentication enabled on Gmail - [ ] App Password generated - [ ] SMTP credentials configured in .env - [ ] Test email sent successfully - [ ] HTML templates created - [ ] Email appears in recipient inbox - [ ] Check spam/junk folder ### Sample Email Service Code ```javascript // backend/services/emailService.js import { sendEmail } from '../config/email.js'; export const EmailService = { async sendOTP(email, otp) { const html = `

OTP: ${otp}

Valid for 10 mins

`; return sendEmail(email, 'OTP Code', html); }, async sendOrderConfirmation(email, order) { const html = `

Order Confirmed

Order ID: #${order.id}

Amount: ₹${order.amount}

`; return sendEmail(email, 'Order Confirmation', html); }, async sendCommissionAlert(email, commission) { const html = `

New Commission

Amount: ₹${commission.amount}

Order: #${commission.order_id}

`; return sendEmail(email, 'Commission Earned', html); } }; ```