How to Build a Shopify Post-Purchase Follow-Up Email with n8n and Gmail

The sale is the easy part. The harder part is the silence right after it, when a new customer is waiting for a package and quietly deciding whether your store was a one-time thing or somewhere they will come back to. Most stores fill that silence with nothing, or with a generic “thanks for your order” that fires the second the checkout completes and is forgotten by the time the box arrives.

A Shopify post-purchase follow-up email built in n8n closes that gap. This workflow waits a few days after each order is fulfilled, drafts a short personalized line about what the customer actually bought, and sends a warm follow-up through your own Gmail account. It costs almost nothing to run and it asks for the review, the reorder, or the reply at the one moment the customer is most likely to give it.

Prefer to skip the setup? Grab the ready-made template → and be up and running in under 10 minutes.

TL;DR

This guide builds a Shopify post-purchase follow-up email in n8n that runs on a daily schedule, pulls orders fulfilled a set number of days ago from Shopify, uses OpenAI to write one friendly personalized sentence about the product, and sends the email through Gmail. It needs no paid apps, costs a few cents a month, and turns the dead air after delivery into reviews, replies, and repeat orders. Build it from scratch or import the template.

What it does

Every morning the workflow asks Shopify a simple question: which orders were fulfilled exactly N days ago? For each one it pulls the customer’s name, email, order number, and the first product they bought. It hands that to OpenAI to write a single natural sentence that references the actual product, drops that sentence into a clean email template, and sends it from your Gmail address.

The customer receives something that reads like you typed it personally a few days after their package landed: a quick check that everything arrived well, a gentle nudge to leave a review, and an open door to reply. No app to install on the storefront, no third-party email platform, no monthly seat fee.

Why it beats the default

Shopify’s built-in order confirmation and most email apps fire on a trigger the instant the order is placed. That is the wrong moment for a relationship email. The customer has not received anything yet, has nothing to react to, and treats the message as a receipt.

Timing the email to fulfillment plus a few days changes the whole tone. The package has arrived, the customer has formed an opinion, and a short personal note lands as thoughtful rather than automated. Three more reasons this approach wins:

• It runs from your own Gmail, so replies come straight back to your inbox and the email inherits your existing sender reputation instead of a shared app domain.
• The personalization is real. Referencing the exact product the customer bought reads completely differently from “Hi {{first_name}}, thanks for shopping with us.”
• You own every line. There is no plan to upgrade, no send limit, and no vendor sitting between you and your customer list.

If you are mapping out a wider automation stack, this fits alongside the other recipes in our n8n Shopify automation guide.

What you need

• An n8n instance (Cloud or self-hosted), version 1.0 or newer.
• A Shopify store with admin access to create a custom app and an Admin API access token.
• A Gmail account connected to n8n through Gmail OAuth2.
• An OpenAI API key on pay-as-you-go billing (optional — you can hardcode a line instead).

Estimated build time: 30–45 minutes from scratch, or under 10 minutes with the template.

How it works — the big picture

┌──────────────────────────────────────────────────────────────┐
│  SHOPIFY POST-PURCHASE FOLLOW-UP                              │
│                                                              │
│  [Schedule 9am] → [Shopify: get orders] → [Code: N days ago] │
│                                               ↓              │
│                        [OpenAI: write line] → [Edit Fields]  │
│                                               ↓              │
│                                          [Gmail: send]       │
└──────────────────────────────────────────────────────────────┘
  

Node-by-node list

Step-by-step build

1 Schedule Trigger (scheduleTrigger)

This is the entry point. It wakes the workflow once a day so you check for newly arrived orders on a steady cadence.

1. Add a Schedule Trigger node.
2. Set the interval to Days, every 1 day.
3. Set the trigger hour to 9 (9am in your instance timezone).

2 Get Shopify Orders (shopify)

This pulls a manageable batch of recent orders that you will narrow down in the next step.

1. Add a Shopify node, resource Order, operation Get Many.
2. Turn Return All on (or set a high limit).
3. Under Filters, set Fulfillment Status to shipped and Updated At Min to ={{ $now.minus({ days: 10 }).toISO() }}.

Pulling a 10-day window keeps the batch small while making sure the order you want (fulfilled around 5 days ago) is always inside it. A typical order item arrives looking like this:

{
  "order_number": 1042,
  "email": "emily.rodriguez@gmail.com",
  "customer": { "first_name": "Emily", "last_name": "Rodriguez" },
  "line_items": [{ "title": "Cedar & Sage Soy Candle" }],
  "fulfillments": [{ "created_at": "2026-06-10T14:30:00-04:00" }]
}

3 Keep N-Day-Old Orders (code)

This is the heart of the timing logic. It keeps only the orders whose fulfillment happened exactly N days ago, so each order is contacted on one day and one day only.

1. Add a Code node, mode Run Once for All Items.
2. Paste the script below and set DAYS_AFTER to your preferred window.

const DAYS_AFTER = 5;
const out = [];

for (const item of $input.all()) {
  const order = item.json;
  const fulfillment = (order.fulfillments || [])[0];
  if (!fulfillment || !order.email) continue;

  const shipped = new Date(fulfillment.created_at);
  const days = Math.floor((Date.now() - shipped.getTime()) / 86400000);
  if (days !== DAYS_AFTER) continue;

  out.push({
    json: {
      email: order.email,
      first_name: order.customer?.first_name || "there",
      order_number: order.order_number,
      product: order.line_items?.[0]?.title || "your order"
    }
  });
}

return out;

4 Write Follow-Up Line (OpenAI)

This generates one short, natural sentence that mentions the product by name, so the email never reads like a mail merge.

1. Add an OpenAI node, resource Text, operation Message a Model.
2. Pick a small, cheap model such as gpt-4o-mini.
3. Add a user message with this prompt:

Write one warm, casual sentence (max 20 words) checking in with a customer
named {{ $json.first_name }} about their recent purchase of
"{{ $json.product }}". No greeting, no sign-off, just the sentence.

The model returns something like: “Hope the Cedar & Sage candle has been filling the room nicely since it arrived!”

5 Build Email (set)

This assembles the three pieces Gmail needs: who it goes to, the subject, and the HTML body. Use the Edit Fields node (Set v3.4) with one assignment per field.

1. Add an Edit Fields node.
2. Add a string field to = ={{ $('Keep N-Day-Old Orders').item.json.email }}.
3. Add a string field subject = =Quick check-in on order #{{ $('Keep N-Day-Old Orders').item.json.order_number }}.
4. Add a string field html with the body below.

Hi {{ $('Keep N-Day-Old Orders').item.json.first_name }},<br><br>
{{ $json.message.content }}<br><br>
If everything's good, a quick review would mean a lot. And if anything's
off, just reply to this email — it comes straight to me.<br><br>
Thanks again,<br>The team

6 Send Follow-Up (gmail)

The final node sends the message from your connected Gmail account.

1. Add a Gmail node, operation Send.
2. To: ={{ $json.to }}
3. Subject: ={{ $json.subject }}
4. Message: ={{ $json.html }}, and set Email Type to HTML.
5. Save the workflow and toggle it Active.

Common mistakes

Cost at realistic volume

The only paid piece is the OpenAI call, and it is tiny. Each follow-up uses roughly 150 tokens in and 30 tokens out on a small model — well under a hundredth of a cent per email.

*Gmail’s free tier sends up to 500 messages per day, which covers most small and mid-size stores. Above that, a Google Workspace account raises the limit to 2,000 per day. Drop the OpenAI node and the running cost is effectively zero.

Frequently asked questions

Related guides

• The complete n8n Shopify automation guide
• Shopify abandoned checkout email sequence with n8n
• Shopify new customer welcome email with Gmail and n8n
• More Shopify automation guides →