What is the SPF record used for in email security?

What is the SPF record used for in email security?

• A. To identify a domain's MX servers
• B. To specify approved sending servers and prevent spoofing
• C. To store SPF keys for TLS encryption
• D. To cache DNS responses for mail servers

Answer: (B)

SPF records specify which sending servers are authorized to send email for a domain, helping prevent spoofing. This policy is published in DNS (usually as a TXT record) and lists permitted IP addresses or hosts. When a recipient mail server receives a message, it can check the domain in the envelope sender and look up its SPF record to verify whether the sending IP is allowed. If the sending server isn’t on the approved list, the SPF check fails, and the email is more likely to be rejected or marked as suspicious. This mechanism stops attackers from forging the from address, and it works best when used alongside DKIM and DMARC. SPF is not about identifying MX servers, storing TLS keys, or caching DNS responses.

SPF records specify which sending servers are authorized to send email for a domain, helping prevent spoofing. This policy is published in DNS (usually as a TXT record) and lists permitted IP addresses or hosts. When a recipient mail server receives a message, it can check the domain in the envelope sender and look up its SPF record to verify whether the sending IP is allowed. If the sending server isn’t on the approved list, the SPF check fails, and the email is more likely to be rejected or marked as suspicious. This mechanism stops attackers from forging the from address, and it works best when used alongside DKIM and DMARC. SPF is not about identifying MX servers, storing TLS keys, or caching DNS responses.