MailKite
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Email deliverability API

Email that lands in the inbox. Prove it in 30 seconds.

MailKite is an email API for developers. Every message goes out authenticated — SPF, DKIM, DMARC — routed across Cloudflare and Amazon SES. Don't take our word for it: send yourself a real one.

live · POST api.mailkite.dev/v1/send
SPF DKIM DMARC

Watch it land in your inbox — not in spam.

Verifying your address creates your free account — that's the whole signup.

Rides on Cloudflare Amazon SES + more tier-1 networks
  • No credit card
  • Unlimited domains, free
  • 50% off first year — beta
Our Tier-1 Networks
Amazon SES Cloudflare Postmark
Switched from SendGrid, inbox placement went from ~92% to ~99% in two weeks.

Mark — AdRender.app

One call. No SDK required.

The same POST /v1/send the demo above runs, as a copy-paste curl. MailKite is an HTTP API first; the SDKs are sugar. 

curl -X POST https://api.mailkite.dev/v1/send \
  -H "Authorization: Bearer $MAILKITE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "you@company.com",
    "subject": "Hello from MailKite",
    "html": "<p>It landed.</p>"
  }'

Or grab an SDK — Node, Python, Ruby, Go, PHP, Java, and CLI. See libraries.

Inbound

Receive is just as fast.

Send an email to the address below and watch it arrive as JSON in real time — a live webhook, not a simulation.

live · email → webhook → JSON
realtime webhook json

Emails to the address below hit our webhook and display here instantly.

Send an email to the webhook →

Or send via POST /v1/send with to set to the address above.

connecting…
webhook events

Waiting for inbound email…

events will appear here in real time

Why it landed

Authenticated mail flies. Everything else drops.

That email cleared SPF, DKIM, and DMARC before it ever reached your provider. Flip the toggle to see what happens to mail that doesn't.

SPF DKIM DMARC
delivery path
your domain Inbox Primary · seen Spam filtered · unseen SPF DKIM DMARC

Auto-routed across Cloudflare · Amazon SES + more — AI-tuned per domain, promoted to the highest tier your sending earns.

Best-path routing

The right provider for every message

Transactional, broadcast, or a brand-new domain — MailKite reads each message and routes it through the provider most likely to land it: Amazon SES, Cloudflare, or Postmark. Warm pools on day one, and an automatic reroute if a network degrades. You never pick a provider or babysit an IP.

provider routing optimal path per message
your sends route engine picks the best provider Postmark transactional Priority lane time-sensitive mail Amazon SES high volume Bulk lane broadcasts & campaigns Cloudflare new domain Warm-up pool shared, warmed for you transactional high volume new domain

MailKite routes each message through the provider most likely to land it — and reroutes automatically if one degrades.

The upgrade queue

Your reputation moves up, automatically

Deliverability isn't a one-time setup — it's earned over time. The longer you send clean mail, the higher you climb. Cloudflare and Amazon SES do the carrying; the intelligence on top is what lands your mail.

provider upgrade queue reputation ↑ as you send
Cloudflare entry Starter pool shared · warmed for you Amazon SES promoted Higher-reputation pool earned by clean sending Priority top tier Best path for your mail matched to your pattern AI review AI review

Nothing to configure. The longer you send clean mail, the higher MailKite promotes your domain.

Best-path routing

Your mail rides Cloudflare, Amazon SES, and other tier-1 networks. MailKite picks the best path for every message — and reroutes if one degrades, so delivery never rides on a single provider.

Automatic promotion

MailKite learns how each domain sends and moves it to the highest-deliverability tier its sending earns. Placement gets better as you go — nothing to configure, no reputation to babysit.

Spam never rides your lane

Abusive senders are kept on a separate, isolated pool that never shares your reputation. A bad actor elsewhere on the network can't drag your inbox placement down.

Compare

What you stop doing

MailKite SendGrid Mailgun
SPF, DKIM, DMARC Configured & monitored for you You publish and maintain You publish and maintain
IP warmup None — handled Manual, or paid dedicated IP Manual, or paid dedicated IP
Networks Cloudflare + Amazon SES, auto-reroute Single network Single network
Reputation Promoted automatically per domain You manage it You manage it
Domains (free tier) Unlimited 1 1
Credit card to start No No (but limited) No (but limited)

Still deciding? Send yourself a test email and judge the result, not the table.

Before you sign up

Is it actually free?

Yes. Unlimited domains, no credit card, no daily send cap. You pay only when volume grows past the free threshold — and the beta rate is 50% off your first year for the first 1,000 customers.

Do I have to set up SPF, DKIM, and DMARC myself?

No. You add a domain and MailKite publishes and rotates the keys, keeps alignment correct, and monitors all three. The test email you just sent went out fully authenticated without you touching a DNS record.

Do I need to warm up an IP?

No. There's no IP to warm or babysit. Every domain starts in a warmed shared pool and is promoted automatically to the highest-deliverability tier its sending earns, across tier-1 networks.

My email already sends from somewhere else. How hard is the switch?

Add your domain, drop in the DNS records we generate, and point your send calls at our API or SMTP relay. Most teams are sending in under 15 minutes, and you can run both in parallel while you cut over.

Ship email that lands

Add a domain, drop in the DNS records, and send on a reputation that climbs on its own. Free, no credit card, 50% off your first year.

Free up to 3,000 emails/mo. $10/mo (beta) when you scale — no credit card.

Get your API key — free Send yourself a test first ↑