n8n-nodes-imap-agent

An n8n community node for IMAP mailbox access with first-class AI Agent support (usableAsTool: true). Read, search, move, flag and download emails from any IMAP server — either as a regular workflow node or as a tool driven by the n8n AI Agent node.

Built on top of imapflow (modern, Promise-based IMAP) and mailparser for RFC822 MIME parsing.

Why another IMAP node?

The existing community node n8n-nodes-imap works well for classic workflows, but was not designed for the n8n AI Agent tool protocol. This package is an independent implementation with three priorities:

1. AI-ergonomic descriptions. Every resource, operation and parameter has a description written for an LLM: what the tool does, when to pick it, what each filter means.
2. Flat, JSON-shaped search input. IMAP search criteria (SINCE, UNSEEN, FROM, etc.) are exposed as a collection with one field per criterion — the LLM fills a JSON object, the node translates it to an IMAP query.
3. Binary-clean downloads. Attachments and .eml files come through as n8n binary data, ready to hand off to Paperless-ngx, S3, a file node, or back to the agent.

Installation

In the n8n UI (self-hosted)

Settings → Community Nodes → Install → package name n8n-nodes-imap-agent → Install.

As a custom node (link or manual install)

# in your n8n instance
cd ~/.n8n/custom
npm install n8n-nodes-imap-agent
# restart n8n

Docker

Mount the custom directory and install inside the container, or extend the image:

FROM n8nio/n8n:latest
USER root
RUN cd /home/node/.n8n/custom && npm install n8n-nodes-imap-agent
USER node

Credentials

Create a credential of type IMAP API.

Gmail / Google Workspace

• Enable 2FA and use an App Password — Google refuses plain passwords over IMAP since 2022.
• Alternatively use OAuth2 (XOAUTH2) and hand over a fresh access token. ⚠️ This node does not refresh tokens on its own — access tokens typically expire after 1 hour. Pair with an upstream HTTP Request / OAuth2 node that refreshes, then pass the token in via expression like ={{ $json.access_token }}. A stale token surfaces as "authentication failed".

Microsoft 365 / Outlook.com

• Basic auth is deprecated. Use OAuth2 (XOAUTH2) with a Graph-registered app (IMAP.AccessAsUser.All scope).

Self-hosted (Dovecot, Stalwart, Mailcow)

• Plain password + TLS 1.2 on port 993.
• For internal CAs: set Allow Self-Signed Certificates to false only after you've installed your CA root in the n8n container — otherwise use true.

Operations

Resource: Email (10)

Resource: Mailbox (7)

List, Create, Delete, Rename, Status, Quota, Test Connection.

Agents should run Mailbox: List once before addressing specific folders, so they know the separator (/, ., /[Gmail]/) and which folders exist.

Batch UIDs

All write operations (Move, Copy, Delete, Mark Read, Mark Unread, Flag, Unflag) accept the batch UIDs field — a single number, a comma list, or an IMAP range:

One call → one IMAP round-trip. A classification workflow that moves 50 mails no longer needs 50 execute() iterations.

Error Handling

When the node is set to Continue On Fail, error items now include full context so a downstream IF / Switch node can branch cleanly:

{
  "error": "IMAP flag add failed: no messages matched \"4217\" in \"INBOX\"",
  "resource": "email",
  "operation": "flag",
  "mailbox": "INBOX",
  "uids": "4217"
}

Trigger: IMAP Trigger

Separate node (group trigger) that starts a workflow when the watched mailbox changes. Uses IDLE when the server supports it, polling otherwise.

Behaviour:

• No backlog replay. On first activation (or after UIDVALIDITY change), the trigger sets its watermark to the current UIDNEXT and only emits subsequent messages.
• State persistence. lastUidNext + uidValidity survive workflow restarts via getWorkflowStaticData. UIDVALIDITY change (mailbox re-indexed) resets the watermark without replaying.
• Reconnect. Exponential backoff (250 ms → 30 s cap) on connection loss. client.on('close' | 'error') triggers a re-connect; the catch-up fetch after reconnect emits anything that arrived while offline.
• Manual test. Clicking "Execute Node" in the editor emits the N most recent messages without touching production state — safe to test an activated workflow.

Resource: Download (2)

• Download Attachments — all attachments of a UID into binary slots, with optional filters:
  • Filename Contains — case-insensitive substring match on the attachment filename.
  • MIME Type — exact (application/pdf), type-wildcard (image/*), or full-wildcard (* / */*). A bare type like image does not match — always include a subtype or wildcard.
  • Max Attachment Size (MB) — default 25. Guards n8n workers against OOM when a mail carries a 500 MB file. Set 0 to disable.
• Download EML — full raw RFC822 message as a single .eml binary.

Example AI Agent workflow

Paste the JSON below into Workflows → Import from clipboard. It's a minimal "triage my inbox" agent: the AI Agent is wired to an OpenAI chat model and is given the IMAP node as a tool. The system prompt is kept short on purpose — the tool descriptions in this package do the heavy lifting.

Replace imap-ai / openai-cred with your actual credential IDs after import.

{
  "name": "IMAP AI Triage (demo)",
  "nodes": [
    {
      "parameters": {},
      "id": "1a",
      "name": "When chat message received",
      "type": "@n8n/n8n-nodes-langchain.chatTrigger",
      "typeVersion": 1,
      "position": [240, 300]
    },
    {
      "parameters": {
        "options": {
          "systemMessage": "Du bist ein E-Mail-Assistent. Nutze das Tool 'IMAP (AI)' um Mails zu suchen, zu lesen oder zu verschieben. Antworte knapp auf Deutsch."
        }
      },
      "id": "1b",
      "name": "AI Agent",
      "type": "@n8n/n8n-nodes-langchain.agent",
      "typeVersion": 1.7,
      "position": [520, 300]
    },
    {
      "parameters": {
        "model": "gpt-4o-mini",
        "options": {}
      },
      "id": "1c",
      "name": "OpenAI Chat Model",
      "type": "@n8n/n8n-nodes-langchain.lmChatOpenAi",
      "typeVersion": 1,
      "position": [520, 500],
      "credentials": { "openAiApi": { "id": "openai-cred", "name": "OpenAI" } }
    },
    {
      "parameters": {
        "resource": "email",
        "operation": "search",
        "mailbox": "INBOX",
        "searchFilters": { "unseen": true },
        "options": { "limit": 20, "newestFirst": true }
      },
      "id": "1d",
      "name": "IMAP (AI)",
      "type": "n8n-nodes-imap-agent.imap",
      "typeVersion": 1,
      "position": [800, 500],
      "credentials": { "imapApi": { "id": "imap-ai", "name": "My IMAP" } }
    }
  ],
  "connections": {
    "When chat message received": {
      "main": [[{ "node": "AI Agent", "type": "main", "index": 0 }]]
    },
    "OpenAI Chat Model": {
      "ai_languageModel": [[{ "node": "AI Agent", "type": "ai_languageModel", "index": 0 }]]
    },
    "IMAP (AI)": {
      "ai_tool": [[{ "node": "AI Agent", "type": "ai_tool", "index": 0 }]]
    }
  }
}

Example chat turns once the workflow is running:

• "Habe ich neue Rechnungen seit Montag?" → Agent calls Email / Search with { subject: "Rechnung", since: "2026-04-20", unseen: true }.
• "Zeig mir Mail 1423" → Email / Get with uid: 1423.
• "Verschiebe sie nach Archive/2026/Rechnungen" → Email / Move with that UID and the target folder.

Local development

git clone https://github.com/Daisytwo/n8n-nodes-imap-ai.git
cd n8n-nodes-imap-ai
npm install
npm run build          # tsc + gulp build:icons
npm run lint           # ESLint with n8n-nodes-base rules
npm test               # Jest unit tests for helpers
npm run dev            # tsc --watch

CI runs lint, build and test on every push and PR against main via GitHub Actions (.github/workflows/ci.yml, Node 20 & 22).

Then link into a local n8n instance:

# inside this repo
npm link

# in your n8n custom-nodes dir (create if missing)
mkdir -p ~/.n8n/custom && cd ~/.n8n/custom
npm init -y 2>/dev/null || true
npm link n8n-nodes-imap-agent

# start n8n — it auto-discovers linked packages
n8n start

Open http://localhost:5678, create an IMAP API credential, add an IMAP (AI) node, or wire it as a tool under an AI Agent node.

Implemented / omitted / known limits

Implemented (19 operations + trigger)

• Mailbox (7): List, Create, Delete, Rename, Status, Quota, Test Connection
• Email (10): Search, Get, Move, Copy, Delete, Mark Read, Mark Unread, Flag, Unflag, Append
• Download (2): Download Attachments (with filename/MIME/size filter), Download EML
• Trigger: IMAP Trigger with IDLE (push) + polling fallback, watermark-based dedupe via UIDNEXT/UIDVALIDITY

Deliberately not included

• Gmail-only thread ops (X-GM-THRID). Non-portable across servers.
• OAuth2 refresh flow. Credentials take a pre-issued access token — pair with an upstream OAuth2 credential node for refresh.

Known limits

• hasAttachment filter is a size heuristic (> 50 KB), not an exact BODYSTRUCTURE scan.
• No connection pool across execute() runs — a fresh IMAP connection per node execution, one socket shared across all items inside that execution.
• Unit tests cover the pure helpers (buildSearchQuery, parseRawEmail, matchesMime). Integration testing against Gmail / Dovecot / Stalwart is manual — there is no mock IMAP server in the suite.
• Delete issues \Deleted + best-effort EXPUNGE (expunged: false in the return when the server refuses UID EXPUNGE — the flag is still set). Gmail behaviour differs (moves to Trash).
• Attachment size cap defaults to 25 MB — larger attachments are silently skipped during Download Attachments. Override via Max Attachment Size (MB) = 0 to disable.

License

MIT ©