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· 6 min read

Free email API — no credit card required

A free email API you can start with no credit card — send and receive over HTTP, read OTP codes, and no surprise charge when you cross the free limit.

“Free” email APIs that demand a credit card up front aren’t really friction-free — a card on file means a threshold away from a surprise bill. A genuinely free email API for developers lets you start with nothing but an email address, send and receive over HTTP, and stay free until you decide to upgrade.

What’s free without a card

Sign up, grab a token, and you have a real email API:

  • Send mail with one HTTP call.
  • Receive — every mailbox has a real receiving address.
  • Read messages as JSON with extracted codes and links.
  • Test inboxes — disposable, for CI.

No card, no “add a payment method to continue.”

Quickstart

# 1. create an inbox (one time)
curl -X POST https://login.ollastack.com/api/mailboxes \
  -H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" \
  -d '{"name":"dev","mode":"agent","handle":"dev"}'

# 2. send
curl -X POST https://login.ollastack.com/api/mailboxes/mbx_.../send \
  -H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" \
  -d '{"to":"you@example.com","subject":"It works","text":"Free, no card."}'

Create a token in Dashboard → Settings → API tokens.

The honest free-tier caps

No-card doesn’t mean unlimited. The send quota is modest and monthly — right for transactional sends, agent mail, and testing. The important part: when you hit it, sending pauses — it doesn’t auto-bill a card you never entered. You upgrade deliberately or you don’t. For high-volume sending you’d add a transactional provider; for free send + receive + test, this is it.

Why no-card matters

A card-required “free” tier is one threshold away from charging you. A no-card tier can’t — which is exactly why it’s the safer place to prototype, run CI, or give an AI agent an inbox without a billing risk.

See the email API overview, free email API service, and free API to send email.

Start free, no card.

Frequently asked questions

Is there a free email API with no credit card?

Yes. Ollastack lets you sign up, get an API token, and send and receive email over HTTP without a credit card. The free tier is metered with a modest monthly send quota; receiving and test inboxes are included.

What can I do for free without a card?

Create mailboxes, send mail, receive replies, read extracted OTP codes and links, and spin up disposable test inboxes for CI — all on the free tier with no card on file.

Why do other 'free' email APIs ask for a credit card?

Many free tiers require a card for verification or to auto-upgrade you when you cross a limit. A no-card free tier can't silently start charging — you stay free until you deliberately choose a paid plan.

What happens when I hit the free limit?

Sending pauses at the quota rather than auto-billing a card you never entered. You upgrade deliberately when you're ready — no surprise charge.

Last updated June 21, 2026. Spotted something out of date? Email hello@ollastack.com.