4. MESSAGE SPECIFICATION

• 4.1. SYNTAX
• 4.2. FORWARDING
• 4.3. TRACE FIELDS
  • 4.3.1. RETURN-PATH
  • 4.3.2. RECEIVED
• 4.4. ORIGINATOR FIELDS
  • 4.4.1. FROM / RESENT-FROM
  • 4.4.2. SENDER / RESENT-SENDER
  • 4.4.3. REPLY-TO / RESENT-REPLY-TO
  • 4.4.4. AUTOMATIC USE OF FROM / SENDER / REPLY-TO
• 4.5. RECEIVER FIELDS
• 4.6. REFERENCE FIELDS
• 4.7. OTHER FIELDS