MSDS Ignorance Example: Email                     <--   ^  --> 

---

Stakeholders: User 1, User 2's ISP, User 2

• User 1 knows all components/features present in own client program
• User 1 doesn't know requirements or capabilities of other stakeholders
• User 2's ISP could have (e.g.)
• aliasing, remailing
• filtering (spam or virus)
• User 2 could have or not have (e.g.)
• encryption, decryption, authentication
• ability to handle MIME
• autoresponder active