Email Services Compared — SendGrid, AWS SES, Mailgun, Postmark, Resend

# Email Services Compared — SendGrid, AWS SES, Mailgun, Postmark, Resend ## Why not just use SMTP from your app? Options: 1. **PHP `mail()`** / Node's `nodemailer` → SMTP via `localhost` — poor deliverability, emails land in spam 2. **Direct SMTP to Gmail** — daily limits, no dashboards, Gmail bans apps that spam 3. **DomainIndia email hosting** — good for small volumes (newsletters), but transactional needs dedicated infra 4. **Email API (SendGrid, SES, etc.)** — purpose-built for transactional, best deliverability For transactional email (>100/day), use an API. Your IP is shared with thousands of good senders; dedicated IPs available for high volumes. ## The five major options ## Decision tree **"Just want it to work, don't care much":** - Small volume: Resend (best DX, 3K/mo free) - Medium: SendGrid or Mailgun - High volume: AWS SES (cheapest) **"Best inbox placement, won't compromise":** - Postmark — industry-leading deliverability, transactional-only policy **"Already use AWS / cost-sensitive":** - AWS SES — $0.10/1K is unbeatable **"Want to include React/HTML templates":** - Resend — ships with `react-email` integration **"Need SMS + Email + WhatsApp unified":** - SendGrid (Twilio owned) or Mailgun + Twilio ## Deliverability — the real differentiator Same SPF/DKIM/DMARC setup, same mail content — different services have different delivery rates. Approximate inbox placement (2026, based on public reports): Margins matter at scale — 2% difference on 1M emails = 20,000 missed customers. ## Setup — all five are similar Pattern: 1. Sign up + verify domain ownership 2. Add SPF + DKIM DNS records they provide 3. Get API key 4. Send via HTTPS POST 5. Configure webhooks for delivery events + bounces ### Example — Resend (simplest) ```bash npm install resend ``` ```typescript import { Resend } from 'resend'; const resend = new Resend(process.env.RESEND_API_KEY); await resend.emails.send({ from: '[email protected]', to: '[email protected]', subject: 'Welcome!', html: '

Thanks for signing up

', }); ``` ### Example — SendGrid ```bash npm install @sendgrid/mail ``` ```typescript import sgMail from '@sendgrid/mail'; sgMail.setApiKey(process.env.SENDGRID_API_KEY); await sgMail.send({ from: '[email protected]', to: '[email protected]', subject: 'Welcome!', html: '

Thanks for signing up

', }); ``` ### Example — AWS SES ```bash npm install @aws-sdk/client-sesv2 ``` ```typescript import { SESv2Client, SendEmailCommand } from '@aws-sdk/client-sesv2'; const ses = new SESv2Client({ region: 'ap-south-1' }); await ses.send(new SendEmailCommand({ FromEmailAddress: '[email protected]', Destination: { ToAddresses: ['[email protected]'] }, Content: { Simple: { Subject: { Data: 'Welcome!' }, Body: { Html: { Data: '

Thanks!

' } }, }, }, })); ``` ## Template management Three approaches: **1. In-code templates** (Resend + react-email): ```tsx import { Html, Head, Body, Heading } from '@react-email/components'; export function WelcomeEmail({ name }) { return ( Welcome {name}! ); } await resend.emails.send({ from: '[email protected]', to: '[email protected]', subject: 'Welcome!', react: , }); ``` Component-driven, previewable, testable. **2. Provider-hosted templates** (SendGrid, Mailgun): Create template in dashboard; reference by ID: ```typescript await sgMail.send({ templateId: 'd-abc123...', dynamicTemplateData: { name: 'Rajesh', orderId: 'ORD-1234' }, }); ``` Marketing team can edit without deploys. **3. MJML + Nunjucks** (self-hosted): MJML compiles to responsive HTML. Template in git, render at send time. See `mjml.io`. ## Webhooks — track what happens Every service sends webhooks for: - `delivered` — receiver accepted - `opened` — user opened (requires tracking pixel) - `clicked` — user clicked link - `bounced` — undeliverable (hard vs soft) - `complained` — user marked as spam - `unsubscribed` — user opted out Handler: ```typescript app.post('/webhook/email', express.raw({ type: 'application/json' }), (req, res) => { // Verify signature (per provider) const events = JSON.parse(req.body); for (const e of events) { if (e.event === 'bounce') { // Add to suppression list db.suppressionList.create({ email: e.email, reason: 'bounce' }); } if (e.event === 'spamreport') { db.user.update({ where: { email: e.email }, data: { suppressed: true } }); } } res.sendStatus(200); } ); ``` **Critical:** never send to suppressed emails. Bounce rate >5% damages your domain reputation. ## India-specific notes - **Mobile numbers for email verification** — some Indian apps require phone + email; plan for both - **Hindi/regional language emails** — all providers support UTF-8; some providers' templates have RTL/Hindi rendering issues — test - **GST on bills** — most providers bill from US; your accountant may need GST self-reverse-charge handling - **Card payments** — Razorpay doesn't work for subscription to US services; Indian international cards work but watch for 3D Secure friction ## Dedicated IP — when to buy Dedicated IP: ₹8,000-₹20,000/mo add-on. Consider when: - Volume >500K/mo - You need predictable deliverability (shared IPs have mixed reputation) - Scheduled bulk sends (newsletters) Warm up dedicated IP slowly — jumping from 0 to 100K/day triggers spam filters. ## Cost comparison (at 100K/month) For 100K/month, AWS SES wins on cost. Postmark wins on deliverability. ## Common pitfalls ## FAQ