Create an email draft in an AI agent's inbox via the AgentMail MPP API.
What it does
This endpoint creates a new email draft inside a specific inbox on AgentMail, an email infrastructure service designed for AI agents. It is part of the broader AgentMail MPP (Micropayment Protocol) gateway at `https://mpp.api.agentmail.to`. The endpoint accepts a POST request to `/v0/inboxes/{inbox_id}/drafts` with a JSON body specifying recipients (to, cc, bcc), subject, text/HTML body, attachments, reply-to addresses, scheduled send time, and labels. On success it returns a Draft object containing the draft_id, inbox_id, labels, timestamps, and all composed fields.
Pricing is fixed at $0.01 per call according to the OpenAPI `x-payment-info` annotation (price: "0.01", pricingMode: "fixed"). Most read operations (list drafts, get draft, list messages, etc.) are priced at $0.00, while write operations like sending messages, creating inboxes ($2.00), and creating domains ($10.00) carry small fixed fees. Authentication is via Bearer token in the Authorization header.
The full AgentMail API exposed through this MPP gateway covers inboxes, messages, threads, drafts, domains, webhooks, pods, allow/block lists, and metrics. Drafts can be updated, deleted, and sent via separate endpoints. The service supports custom domains with DNS verification, attachments (inline and file), scheduled sending, and webhook-based event notifications for bounces, deliveries, and complaints.
Capabilities
Use cases
- —AI agent composes and saves an email draft before sending
- —Automated workflow stages a reply draft for human review
- —Agent prepares a scheduled email to be sent at a future time
- —Bot creates drafts with attachments for outbound campaigns
- —Multi-agent system queues email drafts across dedicated inboxes
Fit
Best for
- —AI agents that need their own email inboxes
- —Automated email workflows requiring draft-then-send patterns
- —Applications needing programmatic email composition with attachments
- —Services that want pay-per-call email without monthly subscriptions
Not for
- —High-volume bulk email marketing (no bulk-send primitives)
- —Human-facing webmail clients expecting IMAP/SMTP access
- —Free email sending — every create-draft call costs $0.01
Quick start
curl -X POST "https://mpp.api.agentmail.to/v0/inboxes/{inbox_id}/drafts" \
-H "Authorization: Bearer $TOKEN" \
-H "Content-Type: application/json" \
-d '{"to":["recipient@example.com"],"subject":"Hello","text":"Draft body"}'Example
Request
{
"cc": [
"cc@example.com"
],
"to": [
"recipient@example.com"
],
"html": "<p>Hi, just following up on our meeting.</p>",
"text": "Hi, just following up on our meeting.",
"labels": [
"follow-up"
],
"subject": "Meeting follow-up"
}Response
{
"cc": [
"cc@example.com"
],
"to": [
"recipient@example.com"
],
"html": "<p>Hi, just following up on our meeting.</p>",
"text": "Hi, just following up on our meeting.",
"labels": [
"follow-up"
],
"preview": "Hi, just following up on our meeting.",
"subject": "Meeting follow-up",
"draft_id": "draft_xyz789",
"inbox_id": "inbox_abc123",
"created_at": "2025-01-15T10:30:00Z",
"updated_at": "2025-01-15T10:30:00Z",
"attachments": []
}Endpoint
Quality
Full OpenAPI 3.1 schema with detailed component definitions and x-payment-info annotations is available. However, the probe did not capture a live 402 MPP challenge on this specific endpoint (returned 404 on HEAD, 403 on GET — expected since the endpoint requires POST with a path parameter). No dedicated docs page was reachable at the MPP gateway. Pricing is inferred from x-payment-info but the currency/settlement method for MPP is not explicitly stated in the probe.
Warnings
- —Probe did not capture a 402 MPP challenge on this endpoint; it returned 404/403 likely because POST with a valid inbox_id is required
- —Price currency and settlement method (e.g. USD, USDC, pathUSD) not explicitly stated in the OpenAPI spec — $0.01 is inferred from the price field
- —No dedicated documentation page found at the MPP gateway origin; docs are at https://docs.agentmail.to/
Citations
- —Create Draft endpoint is POST /v0/inboxes/{inbox_id}/drafts with fixed price 0.01https://mpp.api.agentmail.to
- —AgentMail is the email inbox API for AI agents, raised $6M in seed fundinghttps://mpp.api.agentmail.to
- —Create Inbox costs $2.00, Create Domain costs $10.00, most read operations are freehttps://mpp.api.agentmail.to
- —The API supports inboxes, drafts, messages, threads, domains, webhooks, pods, lists, and metricshttps://mpp.api.agentmail.to