Simple Mail Transfer Protocol
RFC 3462 - 廃止→ RFC 6522
RFC 3463 - Enhanced Status Codes for SMTP (updated by RFC 5248)
RFC 3464 - An Extensible Message Format for Delivery Status Notifications
RFC 3798 - Message Disposition Notification (updates RFC 3461)
RFC 3834 - Recommendations for Automatic Responses to Electronic Mail
RFC 4408 - Sender Policy Framework (SPF) Authorizing Use of Domains in E-Mail, Version 1
RFC 4409 - 廃止→ RFC 6409
RFC 4871 - 廃止→ RFC 6376
RFC 4952 - Overview and Framework for Internationalized Email (updated by RFC 5336)
RFC 4954 - SMTP Service Extension for Authentication (updates RFC 3463, updated by RFC 5248)
RFC 5068 - Email Submission Operations: Access and Accountability Requirements (BCP 134)