Header analysis is an example of an anti-spam approach that checks the routing information on e-mail to determine if it is in a valid format and contains valid information. The routing information, or the header, is the part of the e-mail that contains the sender, the recipient, the subject, the date, and the path of the e-mail. Header analysis can detect spam by looking for inconsistencies, anomalies, or falsifications in the header, such as mismatched domains, spoofed addresses, forged timestamps, or invalid characters34. References: 3: CISSP All-in-One Exam Guide, Eighth Edition, Chapter 6, page 6744: CISSP For Dummies, 7th Edition, Chapter 6, page 205.