Transactional email is complex, and many software teams assume building their own notification system without considering the complexities and size of the undertaking. While sending transactional emails is crucial for delivering important information from products, it's more complicated than expected, requiring ongoing development tasks such as implementing a job queue to counter performance impacts. A clear view of the scope and resources required are essential before deciding whether to build or buy an email notification system. Key features of a successful system include fast integration with an email service provider, easy templating and template management, intuitive orchestration, respecting recipients' preferences, and robust logs and retry mechanisms. Buying a notification system provides immediate value, frees up engineering teams to focus on core product development, and offers advanced capabilities such as reusable templates, multichannel functionality, and optimized deliverability. It also gives businesses a competitive advantage by empowering their product teams from the start, improving customer interaction, and allowing them to quickly implement new opportunities to engage with users.