email.sh — Agent-Native Email

email.sh

Email for agents. No inbox required.

Provision addresses, send and receive email, parse inbound messages — all via API. x402 auth. No signup.


# Get a mailbox in one request
$ curl -X POST https://email.prim.sh/v1/mailboxes \
    -H "X-402-Payment: $PAYMENT_TOKEN" \
    -d '{"domain": "email.sh"}'

# → 402 → pay → 201
{
  "id": "mbx_r8k2n4",
  "address": "[email protected]",
  "created_at": "2026-02-23T06:30:00Z",
  "webhook": null,
  "ttl": 86400
}

# Send email
$ curl -X POST https://email.prim.sh/v1/send \
    -H "X-402-Payment: $PAYMENT_TOKEN" \
    -d '{"from": "[email protected]", "to": "[email protected]",
         "subject": "Task complete", "body": "Your report is ready."}'

x402 auth + payment

Send + Receive

Webhooks for inbound

0 signup required

MCP + REST

Part of agentstack

↓ scroll

How it works

Create mailbox

→

📨

Send / receive

→

🪝

Webhook on inbound

→

🗑

Auto-expire or keep

Mailboxes are ephemeral by default (24h TTL). Extend or make permanent with a single API call.

What agents use it for

Service signups

Agent needs a GitHub account? Provision a mailbox, sign up, receive verification email, extract code, verify. All programmatic.

Notifications

Send task completion emails, error alerts, daily reports. Agents communicating with humans where humans expect it — their inbox.

Inbound processing

Give a mailbox to a data source. Inbound emails hit your webhook as structured JSON. The agent processes, never checks an inbox.

Multi-identity

Spin up 50 mailboxes for 50 tasks. Each has its own address. No shared inbox, no routing rules, no filters. Isolation by default.

Disposable verification

Need an email for a one-time verification? Create a mailbox, poll for the email, extract the link, destroy the mailbox. 30 seconds.

Agent-to-agent

Agents on different platforms communicating via email. The universal protocol. No API integration needed — just SMTP.

API reference

# Mailbox management
POST   /v1/mailboxes              # Create mailbox
GET    /v1/mailboxes              # List your mailboxes
GET    /v1/mailboxes/:id          # Mailbox details
PUT    /v1/mailboxes/:id          # Update TTL, webhook, forwarding
DELETE /v1/mailboxes/:id          # Destroy mailbox

# Sending
POST   /v1/send                   # Send email (text or HTML)
POST   /v1/send/raw               # Send raw MIME

# Receiving
GET    /v1/mailboxes/:id/messages # Poll for messages
GET    /v1/messages/:id           # Get message (headers, body, attachments)
DELETE /v1/messages/:id           # Delete message

# Webhooks (push instead of poll)
PUT    /v1/mailboxes/:id          # Set webhook_url for inbound
# Inbound email → POST to your webhook as JSON:
# { "from", "to", "subject", "body_text", "body_html", "attachments": [...] }

# Custom domains (optional)
POST   /v1/domains                # Add custom domain
GET    /v1/domains/:id/verify     # Check DNS verification

MCP tools

# Your agent gets these tools
tools:
  create_mailbox:
    domain: "email.sh"
    ttl: 3600  # 1 hour
    webhook: "https://my-agent.example/inbound"

  send_email:
    from: "[email protected]"
    to: "[email protected]"
    subject: "Build complete"
    body: "Deployed to production. All tests passing."

  read_messages:
    mailbox: "mbx_r8k2n4"
    unread_only: true

  destroy_mailbox:
    mailbox: "mbx_r8k2n4"

Pricing

Action	Cost	Notes
Create mailbox	$0.001	24h TTL included
Extend mailbox (per day)	$0.001	Or set permanent
Send email	$0.0005	Up to 10MB
Receive email	Free	Included with mailbox
Webhook delivery	Free	3 retries
Custom domain	$0.01/day	DNS verification required
Attachment storage	$0.01/GB/day	Auto-purge with mailbox

Sub-cent pricing. An agent can run a full email workflow for under a penny.

Email is an API call.

Agents don't check inboxes. They poll endpoints and parse JSON.

Read the docs →

or just: curl https://email.prim.sh/v1/mailboxes