Sending email notifications is crucial for maintaining strong relationships with customers, improving user productivity, and driving engagement. However, building an email notification system can be complex due to its five core components: content creation, rules engine, customer preferences, deliverability, and tracking. Empowering the product team through templates, enabling intelligent routing with a rules engine, respecting customer preferences, ensuring deliverability, and tracking behavior are essential for creating a scalable and effective email notification service. Leveraging existing services or solutions can also save time and money by not reinventing the wheel.