• rfc5321 - Simple Mail Transfer Protocol
  • It obsoletes RFC 821, RFC 974, RFC 1869, and RFC 2821 and updates RFC1123 (replacing the mail transport materials of RFC 1123).
• rfc5322 - Internet Message Format
  • This specification is a revision of Request For Comments (RFC) 2822, which itself superseded Request For Comments (RFC) 822
• RFC 1123 - Requirements for Internet Hosts -- Application and Support
• RFC 1651 - SMTP Service Extensions
• RFC 1891 - SMTP Service Extension for Delivery Status Notifications
• RFC 1893 - Enhanced Mail System Status Codes
• RFC 2034 - SMTP Service Extension for Returning Enhanced Error Codes
• RFC 2076 - Common Internet Message Headers
• rfc2045 - MIME: Format of Internet Message Bodies
  • These [MIME] documents are revisions of RFCs 1521, 1522, and 1590, which themselves were revisions of RFCs 1341 and 1342.
• rfc2046 - MIME: Media Types
• rfc2047 - MIME: Message Header Extensions for Non-ASCII Text
• rfc2048 - MIME: Registration Procedures
• rfc2049 - MIME: Conformance Criteria and Examples
• rfc2369 - Mail List Header Fields
• rfc3696 - Application Techniques for Checking and Transformation of Names
• RFC 4686 - Analysis of Threats Motivating DomainKeys Identified Mail (DKIM)
• RFC 4871 - DomainKeys Identified Mail (DKIM) Signatures
• RFC 5585 - DomainKeys Identified Mail (DKIM) Service Overview
• RFC 5863 - DomainKeys Identified Mail (DKIM) Development, Deployment and Operations
• The CAN-SPAM Act: A Compliance Guide for Business