RFC 3459 Critical Content of Internet Mail January 2003 Table of Contents 1. Conventions used in this document..............................3 2. Introduction...................................................3 3. Handling Parameter.............................................4 3.1. REQUIRED..................................................4 3.2. OPTIONAL..................................................5 3.3. Default Values............................................5 3.4. Other Values..............................................5 4. Collected Syntax...............................................6 5. Notification...................................................6 5.1. DSN vs. MDN Generation....................................7 5.2. Summary...................................................7 6. Signed Content.................................................8 7. Encrypted Content..............................................9 8. Status Code...................................................10 9. Requirements for Critical Content.............................11 9.1. Needs....................................................11 9.2. Current Approaches.......................................12 10. The Content Gateway...........................................13 10.1. Integrated Content Gateway..............................14 10.2. Disaggregated Delivery Network..........................14 11. Backward Compatibility Considerations.........................15 12. MIME Interactions.............................................15 12.1. multipart/alternative...................................15 12.2. multipart/related.......................................15 12.3. message/rfc822..........................................15 12.4. multipart/signed........................................16 12.5. multipart/encrypted.....................................16 13. Implementation Examples.......................................16 13.1. Content Gateways........................................16 13.2. Disaggregated Content Gateway...........................17 14. OPES Considerations...........................................18 14.1. Consideration (2.1): One-Party Consent..................18 14.2. Consideration (2.2): IP-layer Communications............18 14.3. Consideration (3.1): Notification - Sender..............18 14.4. Consideration (3.2): Notification - Receiver............18 14.5. Consideration (3.3): Non-Blocking.......................18 14.6. Consideration (4.1): URI Resolution.....................18 14.7. Consideration (4.2): Reference Validity.................19 14.8. Consideration (4.3): Architecture Extensions............19 14.9. Consideration (5.1): Privacy............................19 15. Security Considerations.......................................19 16. IANA Considerations...........................................19 17. References....................................................20 17.1 Normative References.....................................20 17.2 Informative Reference....................................21 18. Acknowledgments...............................................22 Burger Standards Track