Getting started

Quickstart

In a few minutes you'll have a live address that receives mail at your webhook and sends with one API call. Every step works three ways — click through the dashboard, ask the AI assistant, or call the API. Pick a tab in any box below and the whole page follows along.

1. Get your API key

Every call below authenticates with one key. Create a free account and grab your key (mk_live_…) from the dashboard — you'll pass it as Authorization: Bearer mk_live_… on every request. Nothing here runs without it.

Get your API key — free

2. Get a domain

Every address lives on a domain MailKite handles the mail for. You have three ways to get one:

Bring a domain you already own — use myapp.ai or a subdomain like mail.myapp.ai, then publish the DNS records MailKite gives you (step 2).
Register a new domain — search for one and buy it right inside MailKite; we wire up the DNS automatically, so you can skip step 2.
Use a free MailKite subdomain — grab myapp.mailkite.dev or myapp.mailn.app and start instantly, with no DNS to configure.

The example below adds myapp.ai. MailKite returns the DNS records to publish (a registered or free MailKite domain comes pre-configured).

add a domain

Dashboard → Domains
Click  [ + Add domain ]
Type   myapp.ai
Click  [ Add ]

Add the domain "myapp.ai"

const res = await mk.createDomain({ domain: "myapp.ai" });

res = mk.createDomain({"domain": "myapp.ai"})

$res = $mk->createDomain(['domain' => 'myapp.ai']);

Object res = mk.createDomain(Map.of("domain", "myapp.ai"));

res, err := mk.CreateDomain(map[string]any{"domain": "myapp.ai"})

res = mk.createDomain("domain" => "myapp.ai")

curl https://api.mailkite.dev/api/domains \
  -H "Authorization: Bearer <session-token>" \
  -H "Content-Type: application/json" \
  -d '{ "domain": "myapp.ai" }'

response

myapp.ai    ● pending

Publish these DNS records:
  MX    myapp.ai           mx.mailkite.dev   (priority 10)
  TXT   myapp.ai           v=spf1 include:mailkite.dev ~all
  TXT   mailkite._domainkey.myapp…     v=DKIM1; k=rsa; p=…
  TXT   _dmarc.myapp.ai    v=DMARC1; p=none;

[ Copy all ]   [ Verify DNS ]

Added myapp.ai — status pending.
Add these DNS records at your provider, then ask me to verify:
  • MX     →  mx.mailkite.dev (priority 10)
  • TXT    SPF:    v=spf1 include:mailkite.dev ~all
  • TXT    DKIM:   mailkite._domainkey  →  v=DKIM1; k=rsa; p=…
  • TXT    DMARC:  _dmarc  →  v=DMARC1; p=none;

{
  "domain": { "id": "dom_…", "domain": "myapp.ai", "status": "pending" },
  "dns": [
    { "type": "MX",  "name": "myapp.ai", "value": "mx.mailkite.dev", "priority": 10 },
    { "type": "TXT", "name": "myapp.ai", "value": "v=spf1 include:mailkite.dev ~all" },
    { "type": "TXT", "name": "mailkite._domainkey.myapp.ai", "value": "v=DKIM1; k=rsa; p=…" },
    { "type": "TXT", "name": "_dmarc.myapp.ai", "value": "v=DMARC1; p=none;" }
  ]
}

{
  "domain": { "id": "dom_…", "domain": "myapp.ai", "status": "pending" },
  "dns": [
    { "type": "MX",  "name": "myapp.ai", "value": "mx.mailkite.dev", "priority": 10 },
    { "type": "TXT", "name": "myapp.ai", "value": "v=spf1 include:mailkite.dev ~all" },
    { "type": "TXT", "name": "mailkite._domainkey.myapp.ai", "value": "v=DKIM1; k=rsa; p=…" },
    { "type": "TXT", "name": "_dmarc.myapp.ai", "value": "v=DMARC1; p=none;" }
  ]
}

{
  "domain": { "id": "dom_…", "domain": "myapp.ai", "status": "pending" },
  "dns": [
    { "type": "MX",  "name": "myapp.ai", "value": "mx.mailkite.dev", "priority": 10 },
    { "type": "TXT", "name": "myapp.ai", "value": "v=spf1 include:mailkite.dev ~all" },
    { "type": "TXT", "name": "mailkite._domainkey.myapp.ai", "value": "v=DKIM1; k=rsa; p=…" },
    { "type": "TXT", "name": "_dmarc.myapp.ai", "value": "v=DMARC1; p=none;" }
  ]
}

{
  "domain": { "id": "dom_…", "domain": "myapp.ai", "status": "pending" },
  "dns": [
    { "type": "MX",  "name": "myapp.ai", "value": "mx.mailkite.dev", "priority": 10 },
    { "type": "TXT", "name": "myapp.ai", "value": "v=spf1 include:mailkite.dev ~all" },
    { "type": "TXT", "name": "mailkite._domainkey.myapp.ai", "value": "v=DKIM1; k=rsa; p=…" },
    { "type": "TXT", "name": "_dmarc.myapp.ai", "value": "v=DMARC1; p=none;" }
  ]
}

{
  "domain": { "id": "dom_…", "domain": "myapp.ai", "status": "pending" },
  "dns": [
    { "type": "MX",  "name": "myapp.ai", "value": "mx.mailkite.dev", "priority": 10 },
    { "type": "TXT", "name": "myapp.ai", "value": "v=spf1 include:mailkite.dev ~all" },
    { "type": "TXT", "name": "mailkite._domainkey.myapp.ai", "value": "v=DKIM1; k=rsa; p=…" },
    { "type": "TXT", "name": "_dmarc.myapp.ai", "value": "v=DMARC1; p=none;" }
  ]
}

{
  "domain": { "id": "dom_…", "domain": "myapp.ai", "status": "pending" },
  "dns": [
    { "type": "MX",  "name": "myapp.ai", "value": "mx.mailkite.dev", "priority": 10 },
    { "type": "TXT", "name": "myapp.ai", "value": "v=spf1 include:mailkite.dev ~all" },
    { "type": "TXT", "name": "mailkite._domainkey.myapp.ai", "value": "v=DKIM1; k=rsa; p=…" },
    { "type": "TXT", "name": "_dmarc.myapp.ai", "value": "v=DMARC1; p=none;" }
  ]
}

{
  "domain": { "id": "dom_…", "domain": "myapp.ai", "status": "pending" },
  "dns": [
    { "type": "MX",  "name": "myapp.ai", "value": "mx.mailkite.dev", "priority": 10 },
    { "type": "TXT", "name": "myapp.ai", "value": "v=spf1 include:mailkite.dev ~all" },
    { "type": "TXT", "name": "mailkite._domainkey.myapp.ai", "value": "v=DKIM1; k=rsa; p=…" },
    { "type": "TXT", "name": "_dmarc.myapp.ai", "value": "v=DMARC1; p=none;" }
  ]
}

See Domains & DNS for registering, bringing your own domain, and the free subdomains in full.

3. Publish the DNS records

Add the four records to your DNS provider. MX enables receiving; SPF and DKIM let your outbound mail pass authentication and land in the inbox; DMARC ties it together. Then verify:

verify a domain

Dashboard → Domains → myapp.ai
Click  [ Verify DNS ]

Verify the DNS for myapp.ai

await mk.verifyDomain("dom_…");

mk.verifyDomain("dom_…")

$mk->verifyDomain('dom_…');

mk.verifyDomain("dom_…");

_, err := mk.VerifyDomain("dom_…")

mk.verifyDomain("dom_…")

curl -X POST https://api.mailkite.dev/api/domains/dom_…/verify \
  -H "Authorization: Bearer <session-token>"

A domain flips to verified as soon as its MX record resolves to mx.mailkite.dev. We keep checking the rest in the background.

4. Point a webhook

Tell MailKite where to POST inbound mail. Any HTTPS endpoint works (and http://localhost while developing).

point a webhook

Dashboard → Domains → myapp.ai → Webhook
Paste  https://myapp.ai/hooks/mailkite
Click  [ Save ]

Send inbound mail for myapp.ai to https://myapp.ai/hooks/mailkite

await mk.setWebhook("dom_…", { url: "https://myapp.ai/hooks/mailkite" });

mk.setWebhook("dom_…", {"url": "https://myapp.ai/hooks/mailkite"})

$mk->setWebhook('dom_…', ['url' => 'https://myapp.ai/hooks/mailkite']);

mk.setWebhook("dom_…", Map.of("url", "https://myapp.ai/hooks/mailkite"));

_, err := mk.SetWebhook("dom_…", map[string]any{"url": "https://myapp.ai/hooks/mailkite"})

mk.setWebhook("dom_…", "url" => "https://myapp.ai/hooks/mailkite")

curl -X PUT https://api.mailkite.dev/api/domains/dom_…/webhook \
  -H "Authorization: Bearer <session-token>" \
  -H "Content-Type: application/json" \
  -d '{ "url": "https://myapp.ai/hooks/mailkite" }'

Every message to any address on the domain now arrives at your endpoint as JSON. Fire a test event from the dashboard or with POST /api/domains/:id/webhook/test, then read Inbound webhooks to learn the payload — and verify the signature so you only trust real events.

5. Send your first email

Use the key from step 1 (mk_live_…) to send. The from address must be on a verified domain.

send a message

Dashboard → Send
From     hello@myapp.ai
To       ada@example.com
Subject  Your invoice #1042
Body     Thanks! Receipt attached.
Click  [ Send ]

Email ada@example.com from hello@myapp.ai
with subject "Your invoice #1042" and body "Thanks! Receipt attached."

import { MailKite } from "mailkite";

const mk = new MailKite(process.env.MAILKITE_API_KEY);

const { id, status } = await mk.send({
  from: "hello@myapp.ai",
  to: "ada@example.com",
  subject: "Your invoice #1042",
  html: "<p>Thanks! Receipt attached.</p>",
});

import os
from mailkite import MailKite

mk = MailKite(os.environ["MAILKITE_API_KEY"])

res = mk.send({
    "from": "hello@myapp.ai",
    "to": "ada@example.com",
    "subject": "Your invoice #1042",
    "html": "<p>Thanks! Receipt attached.</p>",
})

<?php
$mk = new \MailKite\Client(getenv('MAILKITE_API_KEY'));

$res = $mk->send([
    'from' => 'hello@myapp.ai',
    'to' => 'ada@example.com',
    'subject' => 'Your invoice #1042',
    'html' => '<p>Thanks! Receipt attached.</p>',
]);

MailKite mk = new MailKite(System.getenv("MAILKITE_API_KEY"));

Object res = mk.send(Map.of(
    "from", "hello@myapp.ai",
    "to", "ada@example.com",
    "subject", "Your invoice #1042",
    "html", "<p>Thanks! Receipt attached.</p>"
));

mk := mailkite.New(os.Getenv("MAILKITE_API_KEY"))

res, err := mk.Send(mailkite.Message{
	From:    "hello@myapp.ai",
	To:      "ada@example.com",
	Subject: "Your invoice #1042",
	HTML:    "<p>Thanks! Receipt attached.</p>",
})

require "mailkite"

mk = Mailkite::Client.new(ENV["MAILKITE_API_KEY"])

res = mk.send(
  "from" => "hello@myapp.ai",
  "to" => "ada@example.com",
  "subject" => "Your invoice #1042",
  "html" => "<p>Thanks! Receipt attached.</p>"
)

curl https://api.mailkite.dev/v1/send \
  -H "Authorization: Bearer $MAILKITE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "from": "hello@myapp.ai",
    "to": "ada@example.com",
    "subject": "Your invoice #1042",
    "html": "<p>Thanks! Receipt attached.</p>"
  }'

You'll get back a 202 Accepted with a message id. That's it — you're sending and receiving over your own authenticated domain, with no mail server to run.

Next steps

Inbound webhooks — the full email.received payload and attachments.
Send API — attachments, HTML + text, and in-thread replies.
Agent inboxes & MCP — wire email into an AI agent.
API reference — every endpoint in one place.