Vibe coding · Free vibe coding stack · Part 6

Free email and SMS for vibe coding (2026)

How to send transactional mail and OTP texts from a vibe-coded project — Resend as the start-here, then Brevo, SES, Loops, Mailtrap, and Twilio for SMS.

~12 min read

Part 5 gave you login. Next up is a real sender — magic links, receipts, “your download is ready.” Part 6 is email, with a short SMS row for OTP when you need it.

I run this site’s contact form, newsletter digest, and Playbook fulfillment on Resend (news@ / hello@vibecoderslife.com). Same path I’d hand you in Cursor: one API key, verify the domain, send from it.

Skip Gmail SMTP for product mail. And Resend has no SMS — Twilio is that separate row when you need OTP texts, not a second email API.

Email map

Checked 16 Sep 2026 from official docs. Resend Marketing is a separate 1,000-contact Free plan — not the transactional 3,000-send meter.

SMS (short row)

Country rates vary. Do not send marketing SMS from a trial number and expect it to land. Checked 16 Sep 2026.

Wire it from Cursor

Wire transactional email to Resend using RESEND_API_KEY from .env.
Walk me through: (1) verifying the sending domain (SPF/DKIM),
(2) putting RESEND_API_KEY in .env and .gitignore,
(3) the same env var on the host dashboard,
(4) one contact or magic-link send.
Do not use Gmail SMTP. Do not add a second mail vendor in production.
If we need SMS OTP, add Twilio Verify in a separate change — Resend has no SMS.

Resend (start-here)

Resend Free: 3,000 emails/month, 100 per day, 3 domains, 10,000 automation runs, 30-day retention, ticket support. First paid is Pro at $20/mo: 50,000 emails, no daily cap, 10 domains, 5 webhook endpoints, 100 AI credits/mo. Scale starts higher if you need more volume or dedicated Slack. This is the DX start-here: Node SDK, React Email, webhooks, inbound.

1. Create an API key → RESEND_API_KEY in .env.
2. Add the domain → copy DNS (SPF, DKIM, DMARC). Wait for verify.
3. Send from that domain only. Rotate the key if it hits GitHub.

Brevo

Brevo Free: 300 emails/day (campaigns + transactional) after account approval. Unused daily quota dies at midnight. Branding on Free. First paid is Starter from $9/mo for 5,000 emails/month with no daily cap (higher send tiers cost more; removing the Brevo logo is often an add-on). Pick Brevo when Resend’s 100/day cap is the problem and you are fine with marketing-suite UX.

AWS SES

SES has no classic “first paid tier” — you pay for volume. À la carte outbound is about $0.10 per 1,000 emails; the newer Essentials plan lists about $0.16 per 1,000 for the first 10M/mo band. New accounts still start in the sandbox (verified addresses only) until AWS grants production access. New AWS accounts may get Free Tier credits that can apply to SES — check your Billing dashboard. Use SES when you want cheap scale and will accept IAM/sandbox toil.

Loops

Loops Free: 1,000 subscribed contacts, 4,000 sends in any rolling 30 days, 10 emails/sec, “Powered by Loops” footer. First paid starts around $49/mo for up to 5,000 subscribed contacts: unlimited sends, no branding, transactional included. That is an audience / lifecycle tool. Keep Resend for “forgot password” if Loops is only the product newsletter — or commit to Loops for both, not both vendors firing the same receipt.

Mailtrap

Mailtrap splits products. Email Sandbox Free: 50 test emails/month, 1 sandbox, 10 messages retained — enough to see the HTML, not to load-test. Sandbox Basic starts about $17/mo ($14/mo annual) for 500 tests. Email API Free: 4,000/mo, 150/day, 1 domain. API Basic from $15/mo for 10,000 emails, 5 domains, 3 users, no daily cap. Point preview/staging at sandbox SMTP; production stays Resend.

Twilio SMS

Twilio: sign up, trial credit, no card required to start. There is no fixed “first paid plan” — after trial you pay as you go. SMS starts around $0.0083 to send or receive (US list; HU/PL differ). Verify starts at $0.05 per verification. Use it for OTP, not as the mail provider. Env: TWILIO_ACCOUNT_SID, TWILIO_AUTH_TOKEN, Verify service SID.

Free vs paid (the honest cliffs)

• Resend — Pro ($20/mo) when you blow 100/day (a small list on send day) or 3k/month — unlocks 50k and drops the daily cap.
• Brevo — Starter ($9/mo) when 300/day or branding is the issue; you buy monthly send volume instead.
• Loops — paid (~$49/mo) when you pass 1,000 subscribed contacts or need unlimited sends without the footer.
• Mailtrap — Sandbox Basic when 50 tests/mo is too small; API Basic when Free API caps bite (keep production on Resend).
• SES — production access + IAM toil; cheap volume, no friendly DX start-here.
• Twilio — trial ends; SMS/Verify are never “unlimited free.”

Practical tips

• DNS first — unverified domains go to spam. Wait for Resend’s green checks.
• Mailtrap in preview, Resend in prod — same code path, different env.
• Do not double-send — Loops or Resend for broadcasts, not both.
• SMS is a separate product — consent, sender IDs, and country rates.

What’s next in Free vibe coding stack

Coming later: Part 7 — monitoring (GSC + GA4), then Part 8 — payments (Stripe Checkout). Those guides are not live yet — no links until they ship.

Browse tools we actually use on vibecoderslife.com/tools. Resend is listed there as a plain URL.

FAQ

How do I add free transactional email?

Create a Resend API key, verify the domain, put RESEND_API_KEY in .env and on the host, and paste the Cursor prompt above.

Resend vs Brevo vs Loops?

Resend for API-first transactional (what I use on this site). Brevo for a higher daily free send inside a marketing suite. Loops for contact-based SaaS lifecycle. Pick one production sender.

Does Resend send SMS?

No. Use Twilio Verify / SMS. Keep Resend for email.

Can I use Gmail for the product?

Not if you care about deliverability or App Passwords breaking. Use Resend (or SES at scale).

Do I need a credit card?

Not for Resend Free, Brevo Free, Loops Free, Mailtrap Free, or Twilio trial. AWS and paid upgrades need billing.