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Solution

Transactional email from one API call.

Send receipts, password resets, and verification emails from your own SPF/DKIM/DMARC-aligned domain with a single REST call — or any of eight SDKs and a CLI. Inbound and outbound share one quota.

Why it fits

What you get

Your domain, aligned auth

Mail sends from your domain with SPF, DKIM, and DMARC aligned, so it authenticates as you and lands where it should.

One quota, in and out

Sending shares the same account and monthly quota as receiving — no second bill, no separate sending product to provision.

Replies thread

Set inReplyTo with a message-id and MailKite writes the threading headers, so replies to your notifications thread cleanly.

SDKs, CLI, and MCP

Clean SDKs in eight languages, a CLI, and an MCP server — send from your app, a script, or an agent with the same API.

How it works

Three steps to live

  1. 1

    Verify your domain

    Add SPF and DKIM records; MailKite checks them and unlocks sending aligned to your domain.

  2. 2

    Call /v1/send

    POST from, to, subject, and html/text with your API key — or use an SDK method. That's the whole send.

  3. 3

    Track and reply

    Watch delivery in the dashboard, and thread replies by referencing the message-id on the next send.

Show me

POST /v1/send

One authenticated POST — or one SDK call — sends from your own SPF/DKIM-aligned domain.

json
POST https://api.mailkite.dev/v1/send
Authorization: Bearer mk_live_…
Content-Type: application/json

{
  "from": "MyApp <no-reply@myapp.ai>",
  "to": "ada@example.com",
  "subject": "Reset your password",
  "html": "<p>Tap to reset: <a href=\"https://myapp.ai/r/–\">reset</a></p>",
  "text": "Reset your password: https://myapp.ai/r/–"
}
In the box

What's included

Questions

Is this for marketing blasts or transactional mail?

MailKite targets transactional and inbound-first workloads — receipts, resets, verifications, notifications — sent from your own domain. For very high-volume marketing sending, evaluate against your specific volume and deliverability needs.

What do I need before I can send?

A domain with SPF and DKIM records added and verified. Once it passes, you can send to anyone — there's no sandbox or production-access request.

Can an agent send too?

Yes — the same Send API is available over the hosted MCP server and Claude Code plugin, plus the CLI and eight SDKs.

Keep reading

Ready to build?

Start free on unlimited domains — no credit card. Or browse the other solutions.