Unlock Digital Detective Skills with the 2026 Forensics Challenge – Solve the Cyber Mysteries!

An indication that an email sender’s IP address is authorized to send emails for a domain is represented by the "Received-SPF: Pass" result. SPF, which stands for Sender Policy Framework, is an email validation protocol designed to detect forging sender addresses during the delivery of the email.

When you see "Received-SPF: Pass," it confirms that the sender's IP address is listed in the published SPF record for that domain. This suggests that the domain owner has explicitly authorized that IP to send emails on its behalf, thereby helping to establish the legitimacy of the email and reduce the likelihood of spam or phishing attempts.

The other outcomes — Neutral, Fail, and None — do not confirm authorization. "Neutral" indicates that while there is no clear indication of authorization, the sender's IP is also not explicitly forbidden. "Fail" suggests that the IP address is not allowed to send email for that domain, raising concerns about potential spoofing or spam. "None" means that no SPF policy is published for the domain, leading to uncertainty regarding authorized senders. Therefore, "Received-SPF: Pass" is the only option confirming that the IP address is authorized.