Are there other security-related email headers?

Received headers: trace message path through servers, revealing routing and potentially suspicious detours. Each server adds its Received header.

X-Originating-IP: records client IP address originating the message, useful for identifying actual sender location beyond domain.

X-Spam-Status/X-Spam-Score: many filters add headers indicating spam evaluation results. Useful for understanding why messages were classified.

DKIM-Signature: the actual cryptographic signature, which can be examined for signing domain, algorithm, and covered headers.