How to Automate Post-Purchase Email Sequences

I set up this system to build post-purchase nurture sequences that drive reviews and repeat purchases. The moment after purchase is peak engagement. Most businesses waste it with a generic receipt.

This sends the right message at the right time after every order.

What You Need Before Starting

• Python 3.8+ with requests
• Anthropic API key
• ESP API access
• SQLite for tracking

Step 1: Set Up Data Collection

import sqlite3
from datetime import datetime

db = sqlite3.connect("email_system.db")
db.execute('''CREATE TABLE IF NOT EXISTS email_data (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    email TEXT, metric TEXT, value REAL,
    created_at TEXT
)''')
db.commit()

Step 2: Build the AI Layer

import anthropic
from dotenv import load_dotenv

load_dotenv()
client = anthropic.Anthropic()

def process_email_data(input_data, task_type):
    message = client.messages.create(
        model="claude-sonnet-4-20250514",
        max_tokens=1024,
        system="You are an email marketing specialist. Generate actionable outputs.",
        messages=[{"role": "user", "content": f"Task: {task_type}. Data: {input_data}."}]
    )
    return message.content[0].text

Step 3: Connect to ESP

import requests
import os

def esp_action(endpoint, payload):
    return requests.post(
        f"https://api.convertkit.com/v3/{endpoint}",
        json={**payload, "api_key": os.getenv("ESP_API_KEY")}
    ).json()

Step 4: Schedule and Monitor

def daily_report():
    rows = db.execute("SELECT metric, AVG(value) FROM email_data WHERE created_at > date('now', '-1 day') GROUP BY metric").fetchall()
    for metric, avg in rows:
        print(f"{metric}: {avg:.2f}")

0 7 * * * cd /app && python run_email_system.py

What to Build Next

Add performance benchmarking that compares your metrics against industry averages and flags when you fall below standard.

Related Reading

• Prompt: Write a Product Launch Email Sequence - how AI transforms email marketing operations
• AI for Email Marketing Automation - how AI transforms email marketing operations
• From Overwhelmed to Automated - framework for deciding what to automate first