Agent email Agent email

Build a support inbox agent

An inbox agent is an address that answers its own mail. Point support@ at one and every inbound message is read, answered in-thread, and — when it's over the agent's head — handed to a human. No webhook to host, no loop to run.

1. Turn an address into an agent

It's one route with action: "agent". The agentPrompt is the whole program — what it answers, how it sounds, and when to escalate:

create the agent

// One route turns support@ into an agent. The prompt is the program.
mailkite_create_route({
  match: "support@yourdomain.com",
  action: "agent",
  agentPrompt:
    "You are the support agent for yourdomain.com. Answer billing and account " +
    "questions from our docs. Reply in-thread, warmly and briefly. If you can't " +
    "resolve it, or the sender is upset, escalate to humans@yourdomain.com.",
  agentForwardTo: ["humans@yourdomain.com"]
})

Same thing from the dashboard, if you'd rather not write code:

Dashboard → Routes

Dashboard → Routes → [ + Add route ]
Match      support@yourdomain.com
Receiver   Agent
Prompt     Answer billing & account questions for yourdomain.com.
           Reply in-thread. Escalate anything you can't resolve
           to humans@yourdomain.com.
Click [ Add route ]

2. What happens on each email

When mail hits support@yourdomain.com, MailKite runs the agent against it: it reads the full message, drafts a reply from your prompt, and sends it in-thread so the conversation stays intact. Anything it can't resolve — or that trips your escalation rule — is forwarded to the address in agentForwardTo, with the original attached.

3. Test it

Send it a real email, fire a signed test event, or ask the agent directly to see how it answers before you point traffic at it:

test the agent

// Send a signed test event, or just email support@ and watch it reply
mailkite_test_webhook({ domain: "yourdomain.com" })

// Ask the agent directly, without waiting for mail
mailkite_agent({ address: "support@yourdomain.com",
  message: "Hi, how do I change the card on my account?" })

Tune the prompt until the replies read right, add routes for other addresses (sales@, billing@), and let humans handle only what's escalated.

A little about MailKite

MailKite is programmable email for developers and AI agents. An inbox agent is the whole receive-reason-reply loop collapsed into one route — no server to run, no model to host — and it shares the same verified domain your app already sends from. Manage it over MCP, the SDKs, or the dashboard. Inbox agents are on the free tier.

Next: Inbox agents for prompts, escalation, and multi-address setups, or Send & receive from your agent.