End-to-end encryption ensures that email content is encrypted during transmission and can only be decrypted by the intended recipient. This approach provides robust protection against interception and unauthorized access.
* Encryption of Corporate Network Traffic (Option A): This does not address email confidentiality once the email leaves the corporate network.
* Complex User Passwords (Option B): Enhances account security but does not ensure email confidentiality in transit.
* Digital Signatures (Option D): Ensures authenticity and integrity but does not encrypt the email content.
Reference: ISACA CISA Review Manual, Job Practice Area 4: Protection of Information Assets.