It is difficult to identify easily adaptable software in its completed form. In its nature, the definition of “complete” is unclear. As a result, if one expects perfection in software, software products will never be released; the only alternative is to release software if it runs, and then gradually refine it over time. This results in the implicit conventional wisdom that the “continuous development” of the software is the best quality assurance. This paper looks at the highly capable Windows e-mail software called “Hidemaru Mail.” With current progress in IT, it is possible that the concept of software quality assurance can be applied to a broader array of products and services.