RFC Requests For Comment
SMTP - Simple Mail Transfer Protocol
- RFC 5321 Simple Mail Transfer Protocol
- How email is sent over the wire
- RFC 5322 Internet Message Format
- The structure of email messages, especially headers
MIME - Multimedia Internet Email Extensions
- RFC 2045 - Multipurpose Internet Mail Extensions (MIME) Part One
- The basics of creating a MIME message, headers and encoding
- RFC 2046 - Multipurpose Internet Mail Extensions (MIME) Part Two
- Different media types - text, images, etc - and multipart messages, needed for rich text and attachments
- RFC 2047 - MIME Part Three: Message Header Extensions for Non-ASCII Text
- Internationalized text or glyphs in subject lines or friendly from
Authentication
- RFC 6376 - DomainKeys Identified Mail (DKIM) Signatures
- DKIM, a way to allow a sender to prove they're responsible for a message
- RFC 4408 - Sender Policy Framework (SPF) for Authorizing Use of Domains in E-Mail, Version 1
- SPF, aka Sender Permitted From, aka Sender Policy Framework
Feedback
- RFC 5965 - An Extensible Format for Email Feedback Reports
- Sending automated reports when a user hits the "this is spam" button
- RFC 6430 - Email Feedback Report Type Value: not-spam
More to be added...
