How the pipeline works
When someone sends an email to an address on your domain, Nuntly processes it through a series of stages:Receive
The email arrives at your domain and Nuntly accepts it for processing. Security checks (SPF, DKIM, spam, virus) run automatically on every incoming message.
Parse
Nuntly extracts the message metadata (sender, recipients, subject, headers), body content (plain text and HTML), and attachments.
Route
The recipient address is matched against your inboxes. If an inbox address matches the local part of the recipient (for example,
support in support@yourdomain.com), the message is routed there. If no match is found, it goes to the default catch-all inbox.Store
The message is stored with its full content and threaded into an existing conversation or a new thread based on email headers and subject matching.
Key concepts
| Concept | Description |
|---|---|
| Domain | A verified domain with receiving enabled. You configure MX records to route emails to Nuntly. |
| Inbox | An address-based routing target on a domain (for example, support@yourdomain.com). |
| Thread | A conversation grouping. Messages are threaded by In-Reply-To headers, References headers, or subject matching. |
| Namespace | An optional grouping layer for inboxes, useful for multi-tenant applications. |
| Agent | An AI agent identifier assigned to an inbox, enabling automated processing via webhooks and state management. |
| Message | An individual received or sent email within a thread, including headers, content, and attachments. |
What you can build
Multi-tenant SaaS
Give each customer account their own namespace with isolated inboxes. Each account can have asupport@yourdomain.com and billing@yourdomain.com grouped under a namespace tied to their account ID. Use the externalId field to map your internal tenant IDs directly — no extra lookup table needed. Scope all API queries to a namespace to retrieve only that tenant’s messages and threads.
When a new account signs up, provision their namespace and inboxes programmatically. When an account is suspended or deleted, disable the namespace in a single call.
Agencies
An agency managing email for multiple clients creates one namespace per client. Each client namespace gets a dedicated set of inboxes matched to their domain and workflow. The agency’s backend maps client IDs to namespace IDs viaexternalId and scopes all queries accordingly — inbox lists, thread lists, message retrieval — without any risk of data leaking between clients.
Combine this with webhooks to build a unified inbox view across all clients, with routing logic that sends each incoming message to the right internal team.
AI agent inboxes
Assign an AI agent to any inbox. Every incoming message triggers amessage.agent.triggered webhook so your agent can wake up, read the message, and respond. The agent state API persists conversation context across messages — your agent remembers what was discussed in previous exchanges, carries a rolling summary, and can track custom state like ticket IDs or priority levels.
This pattern works for any workflow where you want an LLM to handle email autonomously: customer intake, lead qualification, order acknowledgment, technical triage. Each agent can have its own namespace and a set of inboxes it manages independently. See AI agent inboxes for a full example with Claude.
Reactive email automation
Email is often the trigger for a workflow, not just a communication channel. When an order confirmation arrives, create a fulfillment task. When an invoice lands in an inbox, start an approval flow. When a monitoring alert fires, open a ticket and notify the on-call engineer. Nuntly extracts full message content — text, HTML, and raw MIME — and makes it available through presigned URLs. Your webhook handler fetches the body, parses whatever structure it contains, and kicks off the right action. Auto-acknowledgment is a common companion pattern: reply to the sender immediately to confirm their request was received, then process it asynchronously.Helpdesk and customer support
Create dedicated inboxes forsupport@, billing@, and technical@ on your domain. Each incoming email becomes a thread that preserves the full conversation history — including replies your team sends from the API. Your team can read unread threads, reply, and forward messages to the right person without leaving your application.
Connect the message.received webhook to your ticketing system via n8n, Make, or Zapier to automatically create and assign tickets. The thread model gives you everything needed to build a lightweight helpdesk directly on top of the API, or to feed a full-featured tool like Zendesk or Linear.
Shared inbox for sales teams
Route all inbound sales inquiries through a singlesales@ inbox. When a new message arrives, a message.received webhook fires and your workflow starts: create a CRM contact, assign the lead to the right rep, log the conversation. Your team replies directly from the inbox and the full thread — including outbound messages — is tracked in one place.
No code server required for basic setups. A webhook pointing to an n8n or Make flow is enough to connect an inbox to a CRM, a Slack channel, or a Notion database.