Agentmail

AgentMail

Email infrastructure for AI agents — create inboxes, send/receive messages, manage threads.

Setup

API key from agentmail.to → Dashboard → API Keys. Configure via gateway.

What Users Ask

• "Create an email inbox for the support agent"
• "Send an email to user@example.com"
• "Check the inbox for new messages"
• "What emails came in today?"
• "Reply to that email"
• "Show me the thread with the customer"

Capabilities

• Create and manage email inboxes (each gets a unique address)
• Send emails from any inbox
• List and read incoming messages
• Reply to messages within threads
• Thread-based conversation tracking
• Webhooks for real-time email notifications (push-based)
• Delete inboxes when done

Response Data

Inbox:

• id — Inbox ID
• email — The inbox's email address
• display_name — Friendly name
• created_at — Creation timestamp

Message:

• id — Message ID
• thread_id — Thread this message belongs to
• from — Sender address
• to — Recipient addresses
• subject — Email subject
• text — Plain text body
• created_at — Timestamp

Thread:

• id — Thread ID
• subject — Thread subject
• message_count — Number of messages
• messages — Messages in the thread (when fetched individually)

Webhooks

AgentMail can push events to your endpoint in real-time via webhooks (powered by Svix).

Event types: message.received, message.sent, message.delivered, message.bounced, message.complained, message.rejected, message.received.spam, message.received.blocked, domain.verified

Signature verification: Each webhook POST includes Svix headers (svix-id, svix-signature, svix-timestamp). The secret returned at creation time is used with Svix libraries to verify authenticity.

Filtering: Webhooks can be scoped to specific inboxes (max 10 per webhook).

Serving the webhook endpoint

The webhook URL must be reachable from the internet. Two approaches:

Tailscale Funnel (preferred if already on Tailscale):

# Expose a local port to the internet via your Tailscale domain
tailscale funnel 8080
# Your URL: https://<machine-name>.<tailnet>.ts.net/hook

No config changes, no DNS, no certs — Tailscale handles it all. Works on any fleet machine that already runs Tailscale.

Cloudflare Tunnel (alternative):

# One-time setup, then:
cloudflared tunnel run --url http://localhost:8080

Gives you a stable *.cfargotunnel.com URL or custom domain.

Connecting to OpenClaw

OpenClaw is pull-based today (cron polling). To handle incoming webhooks, the instance needs a lightweight HTTP listener that:

1. Receives the webhook POST from AgentMail
2. Verifies the Svix signature
3. Writes the event to a file (e.g., events/incoming-email.md)
4. OpenClaw picks it up on next cron cycle, or a reactive workflow triggers

This is OpenClaw's first push-based integration pattern. The webhook receiver is intentionally minimal — a thin HTTP server that authenticates and persists events for OpenClaw to process.

Notes

• Free tier: 3 inboxes, 3,000 emails/month, 3 GB storage, 2 webhook endpoints
• Inboxes get addresses on agentmail.to domain by default
• Custom domains available on paid plans
• Webhook management requires org-level API key (not inbox-scoped)
• API docs: https://docs.agentmail.to