Appendix A. Technology Considerations

このページは RFC 9989 の該当節を要約し, DMARC tags, DNS names, ABNF, IANA values を保持します.

Appendix A discusses S/MIME, method exclusion, the Sender header field, domain existence tests, Organizational Domain discovery issues, and removal of the historic pct tag. These considerations explain technology choices and changes from earlier DMARC practice.