Email system/External Links
- Please sort and annotate in a user-friendly manner and consider archiving the URLs behind the links you provide. See also related web sources.
Best Current Practices (BCPs) - IETF's best recommendations, going beyond the standards.
BCP30 - Anti-Spam Recommendations for SMTP MTAs BCP38 - Defeating Denial of Service Attacks BCP46 - Recommended ISP Security Procedures BCP134 - Email Submission Operations: Access and Accountability Requirements
IANA Registries - Official registries for special domain names, reserved numbers, and protocol parameters.
IANA Protocol Registries - Registries relevant to email systems
Message Header Fields Multipurpose Internet Mail Extensions (MIME) Simple Mail Transfer Protocol (SMTP) Enhanced Status Codes Simple Mail Transfer Protocol (SMTP) Service Extensions