Create daily newsletter digests from Gmail using GPT-4.1-mini

Summary Every day at a set time, this workflow fetches yesterday’s newsletters from Gmail, summarizes each email into concise topics with an LLM, merges all topics, renders a clean HTML digest, and emails it to your inbox.

What this workflow does - Triggers on a daily schedule (default 16:00, server time) - Fetches Gmail messages since yesterday using a custom search query with optional sender filters - Retrieves and decodes each email’s HTML, subject, sender name, and date - Prompts an LLM (GPT‑4.1‑mini) to produce a consistent JSON summary of topics per email - Merges topics from all emails into a single list - Renders a styled HTML email with enumerated items - Sends the HTML digest to a specified recipient via Gmail

Apps and credentials - Gmail OAuth2: Gmail account (read and send) - OpenAI: OpenAi account

Typical use cases - Daily/weekly newsletter rollups delivered as one email - Curated digests from specific media or authors - Team briefings that are easy to read and forward

How it works (node-by-node) - Schedule Trigger - Fires at the configured hour (default 16:00). - Get many messages (Gmail → getAll, returnAll: true) - Uses a filter like: =(from:@.com) OR (from:@.com) OR (from:@.com -"") after:{{ $now.minus({ days: 1 }).toFormat('yyyy/MM/dd') }} - Returns a list of message IDs from the past day. - Loop Over Items (Split in Batches) - Iterates through each message ID. - Get a message (Gmail → get) - Retrieves the full message/payload for the current email. - Get message data (Code) - Extracts HTML from Gmail’s MIME parts. - Normalizes the sender to just the display name. - Formats the date as DD.MM.YYYY. - Passes html, subject, from, date forward. - Clean (Code) - Converts DD.MM.YYYY → MM.DD (for prompt brevity). - Passes html, subject, from, date to the LLM. - Message a model (OpenAI, model: gpt‑4.1‑mini, JSON output) - Prompt instructs: - Produce JSON: { "topics": [ { "title", "descr", "subject", "from", "date" } ] } - Split multi-news blocks into separate topics - Combine or ignore specific blocks for particular senders (placeholders ) - Keep subject untranslated; other values in language - Injects subject/from/date/html from the current email - Loop Over Items (continues) - Processes all emails for the time window. - Merge (Code) - Flattens the topics arrays from all processed emails into one combined topics list. - Create template (Code) - Builds a complete HTML email: - Enumerated items with title, one-line description - Original subject and “from — date” - Safely escapes HTML and preserves line breaks - Inline, email-friendly styles - Send a message (Gmail → send) - Sends the final HTML to your recipient with a custom subject.

Node map | Node | Type | Purpose | |---|---|---| | Schedule Trigger | Trigger | Run at a specific time each day | | Get many messages | Gmail (getAll) | Search emails since yesterday with filters | | Loop Over Items | Split in Batches | Iterate messages one-by-one | | Get a message | Gmail (get) | Fetch full message payload | | Get message data | Code | Extract HTML/subject/from/date; normalize sender and date | | Clean | Code | Reformat date and forward fields to LLM | | Message a model | OpenAI | Summarize email into JSON topics | | Merge | Code | Merge topics from all emails | | Create template | Code | Render a styled HTML email digest | | Send a message | Gmail (send) | Deliver the digest email |

Before you start - Connect Gmail OAuth2 in n8n (ensure it has both read and send permissions) - Add your OpenAI API key - Import the provided workflow JSON into n8n

Setup instructions 1) Schedule - Schedule Trigger node: - Set your preferred hour (server time). Default is 16:00.