# Multi-Agent Email Workflows

AI agents emailing each other across organizations — enabling agent-to-agent commerce, cross-company coordination, and autonomous workflows where multiple agents collaborate through standard email protocols.

## The problem

As AI agents become more capable, they increasingly need to communicate with agents at other organizations. A procurement agent at one company needs to request quotes from a sales agent at another. A logistics agent needs to coordinate shipping with a warehouse agent. A legal review agent needs to exchange contract drafts with a counterparty's agent.

Building custom API integrations between every pair of organizations is impractical. Each integration requires mutual agreement on protocols, authentication, and data formats. It doesn't scale. But there is already a universal, authenticated, asynchronous communication protocol that works across every organization on earth: email.

Email is the original inter-organization API. It has built-in identity verification (DKIM, SPF, DMARC), works across every company regardless of their tech stack, supports attachments for document exchange, and provides a natural audit trail. For multi-agent workflows, email is not a workaround — it is the right protocol.

## How agents solve this

Each organization gives its agent a real email address on their domain. Agents communicate with each other just like human employees would — through email — but they do it faster, more consistently, and around the clock. The conversation flows naturally: one agent sends a request, the other agent processes it and replies, and the exchange continues until the task is complete.

- **Agent-to-agent commerce:** Procurement agents request quotes, supplier agents respond with pricing, purchase orders are confirmed — all via email
- **Cross-company coordination:** Logistics agents coordinate delivery schedules, legal agents exchange contract revisions, support agents escalate to vendor support
- **Internal agent networks:** Multiple agents within one organization communicate via email, creating auditable workflows with clear handoffs
- **Human-in-the-loop:** Agents can escalate to human colleagues when decisions exceed their authority, keeping humans in control of critical choices

## How it works with Robotomail

Robotomail makes it easy to give each agent its own authenticated email address. Both sides of a multi-agent workflow can use Robotomail, or just one — since it's standard email, it works with any email provider on the other end.

**Step 1: Create mailboxes for each agent**

Buyer's procurement agent


```
curl -X POST https://api.robotomail.com/v1/mailboxes \
  -H "Authorization: Bearer rbt_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "address": "procurement",
    "domainId": "dom_buyercorp",
    "displayName": "Procurement Agent — BuyerCorp"
  }'
```

Supplier's sales agent


```
curl -X POST https://api.robotomail.com/v1/mailboxes \
  -H "Authorization: Bearer rbt_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "address": "sales",
    "domainId": "dom_suppliercorp",
    "displayName": "Sales Agent — SupplierCorp"
  }'
```

**Step 2: Buyer agent sends a request for quote**

The procurement agent at BuyerCorp sends an RFQ to the supplier's sales address. This is a standard email — the supplier doesn't need to use Robotomail or any specific API. Their agent just needs to be able to receive email.

Send RFQ


```
curl -X POST https://api.robotomail.com/v1/mailboxes/mbx_procurement/messages \
  -H "Authorization: Bearer rbt_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "to": ["sales@suppliercorp.com"],
    "subject": "RFQ — 500 units Model X-200",
    "bodyText": "Hello,\n\nBuyerCorp is requesting a quote for 500 units of Model X-200, delivered to our Austin warehouse by April 15.\n\nPlease provide:\n- Unit price at 500 qty\n- Lead time from order confirmation\n- Shipping terms\n\nThis is an automated procurement request. Please reply to this email with your quote.\n\nProcurement Agent\nBuyerCorp"
  }'
```

**Step 3: Supplier agent receives and responds**

The supplier's sales agent receives the RFQ via webhook, checks inventory and pricing, and replies with a quote — all automatically.

Incoming RFQ webhook


```
{
  "event": "message.received",
  "mailbox": "sales@suppliercorp.com",
  "message": {
    "id": "msg_rfq_01",
    "from": "procurement@buyercorp.com",
    "subject": "RFQ — 500 units Model X-200",
    "text": "Hello,\n\nBuyerCorp is requesting a quote for 500 units of Model X-200...",
    "threadId": "thr_rfq_01",
    "receivedAt": "2026-03-22T10:00:00Z"
  }
}
```

Send quote reply


```
curl -X POST https://api.robotomail.com/v1/mailboxes/mbx_sales/messages \
  -H "Authorization: Bearer rbt_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "to": ["procurement@buyercorp.com"],
    "subject": "Re: RFQ — 500 units Model X-200",
    "bodyText": "Hello,\n\nThank you for your inquiry. Here is our quote for Model X-200:\n\n- Unit price: $142.50 at 500 qty (list: $165.00)\n- Lead time: 12 business days from order confirmation\n- Shipping: FOB Austin, freight included\n- Quote valid through: April 5, 2026\n\nTo confirm this order, reply with a purchase order number and we will begin production.\n\nSales Agent\nSupplierCorp",
    "inReplyTo": "<msg_rfq_01@robotomail.co>"
  }'
```

**Step 4: Escalate to humans when needed**

The buyer's procurement agent can forward the quote to the human purchasing team for approval, adding its own analysis. Humans stay in control of high-value decisions while agents handle the communication overhead.

Internal escalation


```
curl -X POST https://api.robotomail.com/v1/mailboxes/mbx_procurement/messages \
  -H "Authorization: Bearer rbt_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "to": ["purchasing-team@buyercorp.com"],
    "subject": "Quote Received — 500x Model X-200 from SupplierCorp",
    "bodyText": "I received a quote from SupplierCorp for the X-200 order:\n\n- Unit price: $142.50 (14% below list)\n- Lead time: 12 days\n- Shipping: FOB Austin, freight included\n\nThis is within our budget of $150/unit. Compared to our last order (AlternateSupplier at $148/unit), this saves $2,750 on the order.\n\nReply APPROVE to confirm, or provide counter-offer instructions."
  }'
```

## Key benefits

- **Universal interoperability.** Email works across every organization. No API agreements, no OAuth handshakes, no integration partnerships required. If they have an email address, your agent can communicate with them.
- **Built-in identity and trust.** DKIM signatures prove emails genuinely came from your domain. SPF and DMARC prevent spoofing. Every agent has a verifiable identity.
- **Natural audit trail.** Every message in the conversation is stored, timestamped, and threaded. You have a complete record of every agent interaction for compliance and review.
- **Graceful human handoff.** When agents encounter decisions beyond their authority, they can loop in humans on the same email thread. The context is already there.
- **Works today, not someday.** You don't need to wait for agent-to-agent protocols to be standardized. Email is already the world's most widely adopted inter-organization messaging system.

Read the [API documentation](https://robotomail.com/docs) to get started, or learn more about [why we built Robotomail](https://robotomail.com/blog/introducing-robotomail). You can [create a free account](https://robotomail.com/sign-up) and start building multi-agent workflows today.