Gmail to LINE: AI-Powered Email Summary & Forwarding

Overview

This workflow automatically reads unread emails from your Gmail (or any IMAP-enabled email account), uses a free AI model to analyze and summarize important messages, and forwards the summaries directly to your LINE messaging app. It helps you stay on top of critical emails — like deadlines, payment reminders, meeting invites, and urgent requests — without having to constantly check your inbox.

The workflow is especially useful for busy professionals, parents, or anyone who wants to avoid email overwhelm. By filtering out newsletters and promotions and only sending actionable summaries to LINE, it turns email triage into a fast, mobile-friendly experience.

Node-by-Node Breakdown

• Read emails (IMAP) — Connects to your email server via IMAP to fetch unread emails. This node does not require authentication within n8n; instead, it uses the IMAP credentials (server, port, username, password) you configure in the node settings. It is set to take no further action on the emails after reading them.

• Basic LLM Chain — This is the AI processing core. It uses a prompt you define to analyze each email and determine if it is important (action items, deadlines, urgent requests, etc.) or not (newsletters, promotions). It outputs a structured result with an isImportant boolean and a summary string.

• OpenRouter Chat Model — Provides the AI model for the LLM Chain. It uses OpenRouter, which gives access to multiple LLMs. The configured model is google/gemini-2.5-flash-preview-05-20 (free tier). Authentication is done via Header Auth — you supply an API key as a Bearer token.

• Structured Output Parser — Ensures the AI response is in a consistent JSON format with isImportant (boolean) and summary (string) fields. This makes it easy to use the output in the next node.

• If — A conditional router that checks whether isImportant is true. If important, the email summary is passed to the next node. If not, the workflow ends (no notification sent).

• Send summarized content to messenger — This HTTP Request node sends the summary to LINE's Messaging API. It uses Header Auth with Authorization: Bearer {your channel access token}. The POST request body includes the recipient LINE user ID and the summary text.

• Sticky Notes (4) — Informational notes that explain setup steps, credential configuration, and links to external resources (e.g., OpenRouter, LINE Developers console).

Setup Instructions

1. Email Account (IMAP): Enable IMAP access in your Gmail settings (or use any email provider that supports IMAP). You'll need your email address, IMAP server (e.g., imap.gmail.com), port (usually 993), and an app password if you use 2FA.

2. OpenRouter Account: Sign up for a free account at openrouter.ai. Generate an API key. In the OpenRouter Chat Model node, create a new credential of type 'Header Auth' with:

   • Username: Authorization
   • Password: Bearer {your-api-key}

3. LINE Messaging API: Go to the LINE Developers Console, create a provider and a Messaging API channel. In the channel settings, issue a channel access token (long-lived). In the Send summarized content to messenger node, create a new 'Header Auth' credential with:

   • Username: Authorization
   • Password: Bearer {your-channel-access-token}

4. LINE User ID: You need the recipient's LINE user ID. You can get this by having the user add your LINE bot as a friend and then using the /profile endpoint or a webhook event to capture their ID. Replace U3ec262c49811f30cdc2d2f2b0a0df99a in the node's JSON body with the actual user ID.

Use Cases & Variations

• Daily Digest: Modify the workflow trigger to run on a schedule (e.g., every morning at 8 AM) instead of manually. Add an 'EmailReadIMAP' node that marks emails as read after processing to avoid duplicates.

• Slack or Discord: Replace the LINE HTTP Request node with Slack’s Webhook URL or Discord’s webhook endpoint to send summaries to those platforms instead.

• Multiple Recipients: Use a 'SplitInBatches' node or loop to send summaries to multiple LINE users or Slack channels.

• Custom AI Prompts: Adjust the 'Basic LLM Chain' prompt to categorize emails by urgency, department, or project. You can also ask the AI to extract specific data like invoice amounts or dates.

• Filter by Sender/Label: Add an 'IF' node before the LLM Chain to only process emails from certain senders or with specific keywords in the subject.

• Data Enrichment: Connect a 'Notion' or 'Google Sheets' node to log all summaries for later review or analytics.

{
  "id": "NuEN2uwPicogoHom",
  "meta": {
    "instanceId": "d9375e47b5a4c39b636f79651346004ad9520b52456ecaa1bf171e12a1e17484",
    "templateCredsSetupCompleted": true
  },
  "name": "Gmail to line",
  "tags": [],
  "nodes": [
    {
      "id": "33cb4970-014e-454c-81c4-0511bfae69cd",
      "name": "Read emails (IMAP)",
      "type": "n8n-nodes-base.emailReadImap",
      "position": [
        280,
        220
      ],
      "parameters": {
        "options": {},
        "postProcessAction": "nothing"
      },
      "credentials": {
        "imap": {
          "id": "credential-id",
          "name": "imap Credential"
        }
      },
      "typeVersion": 2
    },
    {
      "id": "7180288e-8260-4707-b714-73be852a0755",
      "name": "Send summarized content to messenger",
      "type": "n8n-nodes-base.httpRequest",
      "position": [
        1380,
        200
      ],
      "parameters": {
        "url": "https://api.line.me/v2/bot/message/push",
        "method": "POST",
        "options": {},
        "jsonBody": "={  \n  \"to\": \"U3ec262c49811f30cdc2d2f2b0a0df99a\",  \n  \"messages\": [  \n    {  \n      \"type\": \"text\",  \n      \"text\": \"{{ $json.output.summary.replace(/\\\\n/g, '\\\\n') }}\"\n    }  \n  ]  \n}",
        "sendBody": true,
        "specifyBody": "json",
        "authentication": "genericCredentialType",
        "genericAuthType": "httpHeaderAuth"
      },
      "credentials": {
        "httpHeaderAuth": {
          "id": "credential-id",
// ... truncated (copy to see full JSON)