Email spoofing is the creation of an email with a forged sender address to intentionally mislead a recipient about its origin. This technique is often used in phishing campaigns and generally attempts to get a user to click a link and share their credentials or reply with sensitive information.

There are two types of From addresses in an email, both of which can be spoofed:

  • Envelope From: This is transmitted during the MAIL FROM command.

  • MIME-Encoded From: This is transmitted after the DATA command during an SMTP transmission. It is not protected by any SMTP mechanism and as such is open to spoofing.

This article relates to SpamTitan Skellig.