drop-email-system-spec

Drop Transactional Email System — Implementation Spec

Project: Drop (Fintech Payment App) Task: MC #1188 Date: 2026-02-17 Author: John (AI Director)

1. Executive Summary

Drop currently has placeholder email templates but no email service layer. This spec defines a production-ready transactional email system covering:

Email service abstraction (provider-agnostic)
Token-based workflows (email verification, password reset)
Transactional emails (welcome, transaction receipt, login alerts)
Database schema for tokens and logs
API endpoints for verification flows
Integration points with existing auth and transaction systems

MVP Recommendation: Resend — Next.js native, simplest setup (5 min vs 30-60 min for SendGrid), generous free tier (3,000 emails/month), React Email integration, automatic DKIM/SPF/DMARC.

2. Provider Comparison

Resend (RECOMMENDED for MVP)

Pros:

Next.js/React native integration (React Email built-in)
Automatic DKIM/SPF/DMARC setup (5 min vs 30-60 min for SendGrid)
Free tier: 3,000 emails/month (100/day limit)
Pro: $20/month for 50,000 emails (no daily limits)
Modern developer experience
Simple API (3 lines to send email)

Cons:

Newer service (launched 2023, less mature than SendGrid)
Lower volume ceiling (enterprise-scale needs SendGrid)
Fewer features (no email validation, inbound parsing, visual template editor)

Best for: Drop MVP — we need transactional emails (not marketing campaigns), React templates, fast setup.

SendGrid

Pros:

Mature platform (better deliverability reputation)
More features: email validation, inbound parsing, visual templates, marketing campaigns
Higher volume handling (enterprise-scale)
Free trial: 100 emails/day for 60 days
Essentials: $19.95/month for 50,000-100,000 emails

Cons:

Complex setup (30-60 min for DNS records)
Separate pricing for marketing campaigns
Dedicated IPs cost extra
Heavier integration (more API complexity)

Best for: Post-MVP if we need email validation, marketing campaigns, or >100k emails/month.

AWS SES

Pros:

Cheapest at scale ($0.10 per 1,000 emails)
No monthly minimums
Built into AWS ecosystem (if we use AWS)

Cons:

Requires AWS account and IAM setup
Manual DNS configuration
No template management
No built-in analytics

Best for: High-volume, low-cost scenario (10M+ emails/year), already on AWS.

MVP Decision: Start with Resend. Migrate to SendGrid if we need email validation or marketing campaigns. All email logic abstracted via src/lib/email.ts — provider swap is 10 lines of code.

Sources:

3. Architecture

3.1 Email Service Layer (`src/lib/email.ts`)

Provider-agnostic email abstraction. All email sending goes through this file.

Current state: Skeleton exists at src/lib/services/email.ts with demo-mode logging only. Action: Replace with production implementation.

Module Interface:

// src/lib/email.ts

export interface EmailParams {
  to: string;
  subject: string;
  htmlBody: string;
  textBody?: string;
}

export interface EmailResult {
  success: boolean;
  messageId?: string;
  error?: string;
}

// Core send function
export async function sendEmail(params: EmailParams): Promise<EmailResult>;

// Template-based helpers
export async function sendWelcomeEmail(userId: string): Promise<EmailResult>;
export async function sendVerificationEmail(email: string, token: string): Promise<EmailResult>;
export async function sendPasswordResetEmail(email: string, token: string): Promise<EmailResult>;
export async function sendTransactionReceipt(txId: string): Promise<EmailResult>;
export async function sendTransferReceivedEmail(userId: string, txId: string): Promise<EmailResult>;
export async function sendLoginAlertEmail(userId: string, ip: string, device: string): Promise<EmailResult>;

Env Vars:

# Provider selection
EMAIL_PROVIDER=resend       # resend | sendgrid | smtp
EMAIL_FROM="Drop <[email protected]>"

# Resend (recommended)
RESEND_API_KEY=re_xxxxx

# SendGrid (alternative)
SENDGRID_API_KEY=SG.xxxxx

# SMTP (fallback)
SMTP_HOST=smtp.sendgrid.net
SMTP_PORT=587
SMTP_USER=apikey
SMTP_PASS=SG.xxxxx

Provider Implementations:

Resend (Primary)

// Resend SDK
import { Resend } from 'resend';

const resend = new Resend(process.env.RESEND_API_KEY);

async function sendViaResend(params: EmailParams): Promise<EmailResult> {
  const { data, error } = await resend.emails.send({
    from: process.env.EMAIL_FROM!,
    to: params.to,
    subject: params.subject,
    html: params.htmlBody,
    text: params.textBody,
  });

  if (error) {
    return { success: false, error: error.message };
  }

  return { success: true, messageId: data?.id };
}

SendGrid (Alternative)

// SendGrid SDK
import sgMail from '@sendgrid/mail';

sgMail.setApiKey(process.env.SENDGRID_API_KEY!);

async function sendViaSendGrid(params: EmailParams): Promise<EmailResult> {
  const msg = {
    to: params.to,
    from: process.env.EMAIL_FROM!,
    subject: params.subject,
    html: params.htmlBody,
    text: params.textBody,
  };

  try {
    const [response] = await sgMail.send(msg);
    return { success: true, messageId: response.headers['x-message-id'] };
  } catch (error) {
    return { success: false, error: (error as Error).message };
  }
}

SMTP (Fallback)

// Nodemailer
import nodemailer from 'nodemailer';

const transporter = nodemailer.createTransport({
  host: process.env.SMTP_HOST,
  port: Number(process.env.SMTP_PORT),
  secure: false, // TLS
  auth: {
    user: process.env.SMTP_USER,
    pass: process.env.SMTP_PASS,
  },
});

async function sendViaSMTP(params: EmailParams): Promise<EmailResult> {
  const info = await transporter.sendMail({
    from: process.env.EMAIL_FROM,
    to: params.to,
    subject: params.subject,
    html: params.htmlBody,
    text: params.textBody,
  });

  return { success: true, messageId: info.messageId };
}

Rate Limiting:

Max 10 emails per user per hour (prevent abuse)
Use existing rate_limits table with key email:{userId}:{hour}
Helper: async function checkEmailRateLimit(userId: string): Promise<boolean>

Retry Logic (Fire-and-Forget for MVP):

No retry for MVP (email service handles retries internally)
Log failures to email_log table for manual review
Post-MVP: Add job queue (BullMQ/Agenda) for guaranteed delivery

Template Loading:

// Load from src/email-templates/*.html
import fs from 'fs';
import path from 'path';

function loadTemplate(name: string): string {
  const templatePath = path.join(process.cwd(), 'src/email-templates', `${name}.html`);
  return fs.readFileSync(templatePath, 'utf-8');
}

// Replace {{placeholders}} with values
function renderTemplate(template: string, data: Record<string, string>): string {
  return template.replace(/\{\{(\w+)\}\}/g, (_, key) => data[key] || '');
}

3.2 Email Templates

Existing templates in src/email-templates/:

welcome.html — Welcome email (placeholder: {{verifyUrl}})
transaction-receipt.html — Transaction confirmation (placeholders: {{transactionDate}}, {{amount}}, {{fromName}}, {{toName}}, etc.)
password-reset.html — Password reset (placeholders: {{resetUrl}}, {{userEmail}})

Templates to CREATE:

1. `email-verification.html`

Purpose: Verify email address (sent after registration) Placeholders:

{{firstName}} — User's first name
{{verifyUrl}} — Verification link with token (1-hour expiry)
{{otpCode}} — 6-digit OTP code (backup method if link doesn't work)

Content:

<h1>Verifiser e-posten din</h1>
<p>Hei {{firstName}},</p>
<p>Klikk på lenken under for å verifisere e-postadressen din:</p>
<a href="{{verifyUrl}}" style="...">Verifiser e-post</a>
<p>Alternativt, skriv inn denne koden: <strong>{{otpCode}}</strong></p>
<p>Lenken utløper om 1 time.</p>

2. `transfer-received.html`

Purpose: Notify user they received money Placeholders:

{{firstName}} — Recipient first name
{{amount}} — Amount received (e.g., "kr 2 500,00")
{{currency}} — Currency code (e.g., "NOK")
{{senderName}} — Sender's name
{{transactionDate}} — Timestamp
{{transactionId}} — Transaction ID

Content:

<h1>Du mottok penger</h1>
<p>Hei {{firstName}},</p>
<p>Du har mottatt <strong>{{amount}} {{currency}}</strong> fra {{senderName}}.</p>
<p>Dato: {{transactionDate}}</p>
<p>Transaksjons-ID: {{transactionId}}</p>
<a href="https://getdrop.no/dashboard" style="...">Åpne Drop</a>

3. `login-alert.html`

Purpose: Security alert for new device/location login Placeholders:

{{firstName}} — User's first name
{{device}} — Device/browser (e.g., "Chrome on macOS")
{{location}} — IP or location (e.g., "Oslo, Norway")
{{timestamp}} — Login time
{{securityUrl}} — Link to account security settings

Content:

<h1>Ny pålogging oppdaget</h1>
<p>Hei {{firstName}},</p>
<p>Vi har oppdaget en pålogging fra en ny enhet:</p>
<ul>
  <li>Enhet: {{device}}</li>
  <li>Plassering: {{location}}</li>
  <li>Tidspunkt: {{timestamp}}</li>
</ul>
<p>Hvis dette ikke var deg, <a href="{{securityUrl}}">endre passordet ditt</a> umiddelbart.</p>

4. `support-ticket-update.html` (Future)

Purpose: Notify user their support ticket has a response Placeholders:

{{firstName}}, {{ticketId}}, {{ticketSubject}}, {{updateUrl}}

3.3 Database Schema

New Tables:

`email_verification_tokens`

-- SQLite
CREATE TABLE IF NOT EXISTS email_verification_tokens (
  id TEXT PRIMARY KEY,
  user_id TEXT NOT NULL REFERENCES users(id),
  token TEXT UNIQUE NOT NULL,  -- UUID v4
  otp_code TEXT NOT NULL,       -- 6-digit code (backup method)
  expires_at TEXT NOT NULL,     -- ISO timestamp, 1 hour from creation
  used_at TEXT,                 -- NULL until verified
  created_at TEXT DEFAULT (datetime('now'))
);

CREATE INDEX IF NOT EXISTS idx_email_verify_user ON email_verification_tokens(user_id);
CREATE INDEX IF NOT EXISTS idx_email_verify_token ON email_verification_tokens(token);

-- PostgreSQL
CREATE TABLE IF NOT EXISTS email_verification_tokens (
  id TEXT PRIMARY KEY,
  user_id TEXT NOT NULL REFERENCES users(id),
  token TEXT UNIQUE NOT NULL,
  otp_code TEXT NOT NULL,
  expires_at TEXT NOT NULL,
  used_at TEXT,
  created_at TEXT DEFAULT (CURRENT_TIMESTAMP)
);

`password_reset_tokens`

-- SQLite
CREATE TABLE IF NOT EXISTS password_reset_tokens (
  id TEXT PRIMARY KEY,
  user_id TEXT NOT NULL REFERENCES users(id),
  token TEXT UNIQUE NOT NULL,  -- UUID v4
  expires_at TEXT NOT NULL,     -- ISO timestamp, 1 hour from creation
  used_at TEXT,                 -- NULL until reset
  created_at TEXT DEFAULT (datetime('now'))
);

CREATE INDEX IF NOT EXISTS idx_pwd_reset_user ON password_reset_tokens(user_id);
CREATE INDEX IF NOT EXISTS idx_pwd_reset_token ON password_reset_tokens(token);

-- PostgreSQL
CREATE TABLE IF NOT EXISTS password_reset_tokens (
  id TEXT PRIMARY KEY,
  user_id TEXT NOT NULL REFERENCES users(id),
  token TEXT UNIQUE NOT NULL,
  expires_at TEXT NOT NULL,
  used_at TEXT,
  created_at TEXT DEFAULT (CURRENT_TIMESTAMP)
);

`email_log`

-- SQLite
CREATE TABLE IF NOT EXISTS email_log (
  id TEXT PRIMARY KEY,
  user_id TEXT REFERENCES users(id),  -- NULL for non-user emails
  template TEXT NOT NULL,              -- Template name (e.g., "welcome", "password-reset")
  recipient TEXT NOT NULL,             -- Email address
  subject TEXT NOT NULL,
  status TEXT NOT NULL CHECK(status IN ('sent','failed')),
  message_id TEXT,                     -- Provider message ID
  error TEXT,                          -- Error message if failed
  sent_at TEXT DEFAULT (datetime('now'))
);

CREATE INDEX IF NOT EXISTS idx_email_log_user ON email_log(user_id);
CREATE INDEX IF NOT EXISTS idx_email_log_status ON email_log(status);
CREATE INDEX IF NOT EXISTS idx_email_log_sent_at ON email_log(sent_at);

-- PostgreSQL
CREATE TABLE IF NOT EXISTS email_log (
  id TEXT PRIMARY KEY,
  user_id TEXT REFERENCES users(id),
  template TEXT NOT NULL,
  recipient TEXT NOT NULL,
  subject TEXT NOT NULL,
  status TEXT NOT NULL CHECK(status IN ('sent','failed')),
  message_id TEXT,
  error TEXT,
  sent_at TEXT DEFAULT (CURRENT_TIMESTAMP)
);

Schema Migration:

Add to src/lib/db.ts in SQLITE_SCHEMA and PG_SCHEMA constants
Tables auto-create on initDb() (existing pattern)

3.4 API Endpoints

POST `/api/auth/verify-email`

Purpose: Verify email with token or OTP code Request:

{
  "token": "uuid-v4-token",  // From email link
  "code": "123456"           // Optional: OTP code (if user can't click link)
}

Response (200):

{
  "data": {
    "verified": true,
    "userId": "usr_xxx"
  }
}

Errors:

400: Missing token/code
404: Token not found
410: Token expired or already used

Logic:

Look up token in email_verification_tokens
Check expiry (expires_at < now() → error 410)
Check used_at IS NOT NULL → error 410
If code provided, validate otp_code matches
Update used_at = now()
Mark user as verified (add email_verified column to users table)
Log to audit log

File: src/app/api/auth/verify-email/route.ts

POST `/api/auth/forgot-password`

Purpose: Request password reset (sends email with token) Request:

{
  "email": "[email protected]"
}

Response (200):

{
  "data": {
    "message": "If the email exists, a reset link has been sent."
  }
}

Logic:

Look up user by email
If user not found → return 200 anyway (security: don't leak account existence)
Generate UUID token, 1-hour expiry
Insert into password_reset_tokens
Send password-reset.html email with {{resetUrl}} = /reset-password?token=xxx
Log to email_log

File: src/app/api/auth/forgot-password/route.ts

POST `/api/auth/reset-password`

Purpose: Reset password with token Request:

{
  "token": "uuid-v4-token",
  "newPassword": "NewP@ssw0rd123"
}

Response (200):

{
  "data": {
    "message": "Password reset successful. You can now log in."
  }
}

Errors:

400: Invalid password (reuse validation from /api/auth/register)
404: Token not found
410: Token expired or already used

Logic:

Look up token in password_reset_tokens
Check expiry and usage (same as verify-email)
Validate new password (8+ chars, 1 uppercase, 1 lowercase, 1 digit, 1 special)
Hash new password (hashPassword())
Update users.password_hash
Mark token used_at = now()
Revoke all user sessions (security: force re-login)
Log to audit log

File: src/app/api/auth/reset-password/route.ts

POST `/api/auth/resend-verification`

Purpose: Resend verification email (if user didn't receive it) Request:

{
  "email": "[email protected]"
}

Response (200):

{
  "data": {
    "message": "If the email exists, a verification email has been sent."
  }
}

Logic:

Look up user by email
If not found → return 200 anyway
If already verified → return 200 (idempotent)
Invalidate old tokens (UPDATE email_verification_tokens SET used_at = now() WHERE user_id = ? AND used_at IS NULL)
Generate new token and OTP
Send verification email
Rate limit: max 3 resends per hour

File: src/app/api/auth/resend-verification/route.ts

3.5 Integration Points

A. Register Flow (MODIFY: `src/app/api/auth/register/route.ts`)

Current state: Lines 107-133 generate OTP for SMS (not implemented). Action: Add email verification.

Additions:

// After user insert (line 92)
import { sendVerificationEmail } from '@/lib/email';
import crypto from 'crypto';

// Generate email verification token
const verifyTokenId = randomId('evt');
const verifyToken = crypto.randomUUID();
const otpCode = String(crypto.randomInt(100000, 1000000)); // 6 digits
const expiresAt = new Date(Date.now() + 60 * 60 * 1000).toISOString(); // 1 hour

await run(
  `INSERT INTO email_verification_tokens (id, user_id, token, otp_code, expires_at)
   VALUES (?, ?, ?, ?, ?)`,
  [verifyTokenId, id, verifyToken, otpCode, expiresAt]
);

// Send verification email
await sendVerificationEmail(email!, verifyToken);

Note: Keep OTP SMS code (lines 109-133) as-is for phone verification. Email verification is separate.

B. Transaction Complete (MODIFY transaction routes)

Files to modify:

src/app/api/transactions/remittance/route.ts (remittance)
src/app/api/transactions/qr-payment/route.ts (QR payment)

After transaction status = 'completed':

import { sendTransactionReceipt, sendTransferReceivedEmail } from '@/lib/email';

// Send receipt to sender
await sendTransactionReceipt(txId);

// If remittance, notify recipient (if they have a Drop account)
if (type === 'remittance' && recipientUserId) {
  await sendTransferReceivedEmail(recipientUserId, txId);
}

Note: Recipient email only if recipient has a Drop account. Otherwise, recipient gets money via bank transfer (no Drop account = no email notification from Drop).

C. Login Alert (MODIFY: `src/app/api/auth/login/route.ts`)

Current state: Sets auth cookie, no device tracking. Action: Add login alert for new devices.

Device fingerprint detection:

import { getClientIp } from '@/lib/middleware';
import { sendLoginAlertEmail } from '@/lib/email';
import crypto from 'crypto';

const ip = getClientIp(request);
const userAgent = request.headers.get('user-agent') || 'Unknown';

// Generate device fingerprint (hash of IP + User-Agent)
const deviceFingerprint = crypto.createHash('sha256')
  .update(`${ip}:${userAgent}`)
  .digest('hex');

// Check if device is new
const existingDevice = await getOne<{ id: string }>(
  "SELECT id FROM sessions WHERE user_id = ? AND device_fingerprint = ?",
  [userId, deviceFingerprint]
);

if (!existingDevice) {
  // New device → send alert
  await sendLoginAlertEmail(userId, ip, userAgent);
}

// Add device_fingerprint to session insert

Schema change:

-- Add to sessions table
ALTER TABLE sessions ADD COLUMN device_fingerprint TEXT;
CREATE INDEX IF NOT EXISTS idx_sessions_device ON sessions(device_fingerprint);

D. Support Ticket Response (FUTURE)

Not in MVP. When support ticket system is built:

POST /api/support/tickets/:id/respond → sends support-ticket-update.html

4. Dependencies

Add to package.json:

{
  "dependencies": {
    "resend": "^4.0.0",           // Resend SDK
    "@sendgrid/mail": "^8.1.0",   // SendGrid SDK (optional, for provider swap)
    "nodemailer": "^6.9.0"        // SMTP fallback
  },
  "devDependencies": {
    "@types/nodemailer": "^6.4.14"
  }
}

Install:

npm install resend @sendgrid/mail nodemailer
npm install -D @types/nodemailer

5. Env Vars

Add to .env.example:

# --- Email Service ---
# Provider: resend (recommended) | sendgrid | smtp
EMAIL_PROVIDER=resend
EMAIL_FROM="Drop <[email protected]>"

# Resend API key (get from resend.com)
RESEND_API_KEY=re_xxxxx

# SendGrid API key (alternative provider)
# SENDGRID_API_KEY=SG.xxxxx

# SMTP fallback
# SMTP_HOST=smtp.sendgrid.net
# SMTP_PORT=587
# SMTP_USER=apikey
# SMTP_PASS=SG.xxxxx

Production setup (Resend):

6. File List

Files to CREATE:

src/lib/email.ts                                    # Email service layer
src/email-templates/email-verification.html         # Email verification template
src/email-templates/transfer-received.html          # Transfer received template
src/email-templates/login-alert.html                # Login alert template
src/app/api/auth/verify-email/route.ts              # Email verification endpoint
src/app/api/auth/forgot-password/route.ts           # Password reset request endpoint
src/app/api/auth/reset-password/route.ts            # Password reset endpoint
src/app/api/auth/resend-verification/route.ts       # Resend verification endpoint

Files to MODIFY:

src/lib/db.ts                                       # Add email_verification_tokens, password_reset_tokens, email_log tables
src/app/api/auth/register/route.ts                  # Add email verification send
src/app/api/auth/login/route.ts                     # Add login alert for new devices
src/app/api/transactions/remittance/route.ts        # Add transaction receipt email
src/app/api/transactions/qr-payment/route.ts        # Add transaction receipt email
src/lib/services/email.ts                           # DELETE (replaced by src/lib/email.ts)
.env.example                                        # Add EMAIL_* env vars
package.json                                        # Add resend, @sendgrid/mail, nodemailer deps

Total: 8 new files, 7 modified files.

7. Acceptance Criteria

Email Service Layer:

sendEmail() sends via Resend in production
sendEmail() logs to console in demo mode
sendEmail() falls back to SMTP if Resend fails
All template helpers (sendWelcomeEmail(), etc.) render templates correctly
Rate limiting blocks >10 emails/user/hour

Database:

All tables created on initDb()
Tokens auto-expire after 1 hour
email_log table logs all sent/failed emails

API Endpoints:

POST /api/auth/verify-email verifies token and OTP
POST /api/auth/verify-email rejects expired tokens (410)
POST /api/auth/forgot-password sends reset email
POST /api/auth/reset-password updates password
POST /api/auth/resend-verification resends email
All endpoints rate limited (10 req/min per IP)

Integration:

Registration sends verification email
Transaction completion sends receipt to sender
Transfer completion sends notification to recipient (if Drop user)
Login from new device sends security alert

Templates:

All templates render with correct placeholders
All templates display correctly in Gmail, Outlook, Apple Mail
All templates mobile-responsive (375px width)

Provider Setup:

Resend domain verified (getdrop.no)
DKIM, SPF, DMARC records added to DNS
API key set in production env
Test email sent successfully

8. Implementation Plan

Phase 1: Email Service Layer (2h)

Create src/lib/email.ts with Resend integration
Add Resend dependency
Set up env vars
Test send via Resend dashboard

Phase 2: Database Schema (1h)

Add 3 tables to src/lib/db.ts
Test initDb() creates tables correctly

Phase 3: API Endpoints (3h)

Create 4 API routes (verify, forgot, reset, resend)
Add validation and rate limiting
Test with Postman/curl

Phase 4: Templates (2h)

Create 3 new templates (email-verification, transfer-received, login-alert)
Test rendering with placeholders
Test display in Gmail/Outlook

Phase 5: Integration (2h)

Modify register route (send verification email)
Modify transaction routes (send receipts)
Modify login route (send alert)
Test end-to-end flows

Phase 6: Production Setup (1h)

Set up Resend account
Verify domain (getdrop.no)
Add DNS records
Generate API key
Deploy to staging

Total: 11 hours

9. Rollout Strategy

Staging:

Deploy to staging environment
Test all email flows with real email addresses
Verify DNS records propagated
Check spam score (mail-tester.com)

Production (Gradual):

Enable email verification for NEW users only
Monitor email_log for failures
After 1 week: enable password reset
After 2 weeks: enable transaction receipts
After 3 weeks: enable login alerts

Monitoring:

Daily check of SELECT * FROM email_log WHERE status = 'failed'
Alert if >5% failure rate
Weekly review of Resend dashboard (bounce rate, spam rate)

10. Success Metrics

Week 1:

0 email send failures
<1% bounce rate
<0.1% spam rate

Month 1:

>90% email open rate (verification, password reset)
>50% email open rate (transaction receipts)
0 support tickets about missing emails

Quarter 1:

Email verification integrated into BankID flow
Transaction receipts sent for 100% of transactions
Login alerts sent for 100% of new devices

END OF SPEC

drop-accessibility-spec

drop-analytics-bi-spec

drop-customer-support-spec

drop-dispute-handling-spec

drop-email-system-spec

drop-fx-transparency-spec

drop-load-testing-spec

drop-localization-spec

drop-make-integration-plan

drop-marketing-infra-spec

drop-mvp-pipeline-plan

drop-onboarding-flow-spec

drop-push-notifications-spec

drop-rebrand-plan

drop-sms-otp-spec

drop-supporting-systems-plan

drop-transaction-failure-spec

drop-validation-hardening-plan

Page: Accounts

Page: Dashboard

Page: Landing

Page: Login

Page: Notifications

Page: Profile

Page: Register

Page: Scan

Page: Send

Page: Transactions

drop-email-system-spec

Drop Transactional Email System — Implementation Spec

1. Executive Summary

2. Provider Comparison

Resend (RECOMMENDED for MVP)

SendGrid

AWS SES

3. Architecture

3.1 Email Service Layer (src/lib/email.ts)

Resend (Primary)

SendGrid (Alternative)

SMTP (Fallback)

3.2 Email Templates

1. email-verification.html

2. transfer-received.html

3. login-alert.html

4. support-ticket-update.html (Future)

3.3 Database Schema

email_verification_tokens

password_reset_tokens

email_log

3.4 API Endpoints

POST /api/auth/verify-email

POST /api/auth/forgot-password

POST /api/auth/reset-password

POST /api/auth/resend-verification

3.5 Integration Points

A. Register Flow (MODIFY: src/app/api/auth/register/route.ts)

B. Transaction Complete (MODIFY transaction routes)

C. Login Alert (MODIFY: src/app/api/auth/login/route.ts)

D. Support Ticket Response (FUTURE)

4. Dependencies

5. Env Vars

6. File List

7. Acceptance Criteria

8. Implementation Plan

9. Rollout Strategy

10. Success Metrics

3.1 Email Service Layer (`src/lib/email.ts`)

1. `email-verification.html`

2. `transfer-received.html`

3. `login-alert.html`

4. `support-ticket-update.html` (Future)

`email_verification_tokens`

`password_reset_tokens`

`email_log`

POST `/api/auth/verify-email`

POST `/api/auth/forgot-password`

POST `/api/auth/reset-password`

POST `/api/auth/resend-verification`

A. Register Flow (MODIFY: `src/app/api/auth/register/route.ts`)

C. Login Alert (MODIFY: `src/app/api/auth/login/route.ts`)