> ## Documentation Index > Fetch the complete documentation index at: https://docs.sequenzy.com/llms.txt > Use this file to discover all available pages before exploring further. # Send Email with Express > Send transactional emails using Sequenzy and Express # Send Email with Express This guide shows you how to send transactional emails using Sequenzy in an Express application. ## Prerequisites * A Sequenzy account with an [API key](/authentication) * A [verified sending domain](/guides/domain-verification) * Node.js 18+ installed ## 1. Install Install the Sequenzy SDK and Express: ```bash npm theme={null} npm install sequenzy express ``` ```bash pnpm theme={null} pnpm add sequenzy express ``` ```bash bun theme={null} bun add sequenzy express ``` For TypeScript support: ```bash theme={null} npm install -D @types/express typescript ``` ## 2. Create Your Server Create a basic Express server that sends emails: ```ts index.ts theme={null} import express, { Request, Response } from "express"; import Sequenzy from "sequenzy"; const app = express(); app.use(express.json()); const client = new Sequenzy({ apiKey: process.env.SEQUENZY_API_KEY!, }); app.post("/send", async (req: Request, res: Response) => { const { email, firstName } = req.body; const { data, error } = await client.transactional.send({ to: email, subject: "Welcome to Our Platform!", body: `

Welcome, ${firstName}!

Thanks for signing up.

`, }); if (error) { return res.status(400).json({ error }); } return res.status(200).json({ data }); }); app.listen(3000, () => { console.log("Server running at http://localhost:3000"); }); ``` ## 3. Run Start your server: ```bash theme={null} npx tsx index.ts ``` Send a test request: ```bash theme={null} curl -X POST http://localhost:3000/send \ -H "Content-Type: application/json" \ -d '{"email": "user@example.com", "firstName": "John"}' ``` ## Using Templates Instead of inline HTML, use pre-built templates from the Sequenzy dashboard: ```ts theme={null} app.post("/send-welcome", async (req: Request, res: Response) => { const { email, firstName } = req.body; const { data, error } = await client.transactional.send({ to: email, slug: "welcome-email", variables: { firstName, dashboardUrl: "https://app.example.com/dashboard", }, }); if (error) { return res.status(400).json({ error }); } return res.status(200).json({ data }); }); ``` ## Using React Email For complex email templates, use [React Email](https://react.email) with Express: ```bash theme={null} npm install @react-email/components @react-email/render ``` Create a template: ```tsx emails/welcome-email.tsx theme={null} import { Body, Button, Container, Head, Heading, Html, Preview, Text, } from "@react-email/components"; import * as React from "react"; interface WelcomeEmailProps { firstName: string; dashboardUrl: string; } export function WelcomeEmail({ firstName, dashboardUrl }: WelcomeEmailProps) { return ( Welcome to our platform Welcome, {firstName}! Thanks for signing up. Get started by visiting your dashboard: ); } ``` Use it in your route: ```ts theme={null} import { render } from "@react-email/render"; import { WelcomeEmail } from "./emails/welcome-email"; app.post("/send-welcome", async (req: Request, res: Response) => { const { email, firstName } = req.body; const html = await render( WelcomeEmail({ firstName, dashboardUrl: "https://app.example.com/dashboard", }) ); const { data, error } = await client.transactional.send({ to: email, subject: "Welcome to Our Platform!", body: html, }); if (error) { return res.status(400).json({ error }); } return res.status(200).json({ data }); }); ``` ## Error Handling Add proper error handling for production: ```ts theme={null} app.post("/send", async (req: Request, res: Response) => { try { const { email, firstName } = req.body; if (!email || !firstName) { return res .status(400) .json({ error: "Email and firstName are required" }); } const { data, error } = await client.transactional.send({ to: email, slug: "welcome-email", variables: { firstName }, }); if (error) { console.error("Email sending failed:", error); return res.status(400).json({ error }); } return res.status(200).json({ data }); } catch (err) { console.error("Unexpected error:", err); return res.status(500).json({ error: "Internal server error" }); } }); ``` ## Next Steps Explore all available React Email components Learn more about transactional emails