Programmable email in Ruby

Drive email entirely from Ruby: send with one call, receive every inbound message as parsed JSON on a webhook, and give any app or AI agent its own inbox on a domain you control — with no mail server to run.

Install

Add the Ruby library:

gem install mailkite

Send an email

One endpoint, one API key — over your own authenticated domain. Send API reference →

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>"
)

Receive email as a webhook

Point your domain's MX at MailKite and every message arrives as parsed JSON — verify the signature, then handle it. No IMAP, no mail server.

require "sinatra"
require "json"
require "mailkite"

post "/hooks/mailkite" do
  raw_body = request.body.read
  sig = request.env["HTTP_X_MAILKITE_SIGNATURE"]
  halt 401 unless Mailkite.verify_webhook(sig, raw_body, ENV["MAILKITE_WEBHOOK_SECRET"])
  event = JSON.parse(raw_body)
  # ...handle event["type"] == "email.received"
  content_type :json
  Mailkite.reply_ok # {"status":"ok"}
end

Go deeper: Email to webhook: the complete guide, or give an AI agent its own inbox.

Unlimited domains ·Unlimited mailboxes ·3,000 emails/mo — 100 emails/day. Pricing →