Sender Addresses in Email

• Envelope Sender Address (see RFC-2821)

• • Contained in the “MAIL FROM” and “HELO” SMTP commands
  • Usually stored in the “Return-Path” email header
  • Used during transport of a message between mail servers
  • Used to return the message to the sender in case of delivery failure
  • Usually not displayed to the user by mail programs

• Header Sender Addresses (see RFC-2822)

• • Contained in the “From” or “Sender” email headers
  • Is displayed to users by mail programs
  • Generally, mail servers don’t care about this address; it’s not relevant to delivery