How does the sender policy framework (SPF) help reduce spoofed emails?

The sender policy framework (SPF) helps to reduce spoofed emails primarily by providing a list of IP address ranges for specific domains that are authorized to send emails on behalf of those domains. When an email is received, the email server can perform a lookup to check if the sending IP address matches the authorized IP addresses listed in the domain's SPF record. If there is a match, it indicates that the email is likely genuine and comes from a legitimate source.

This validation process helps to protect both the sender's and recipient's email systems from being misled by fraudulent emails that may appear to be from a trusted domain but are actually sent from unauthorized servers. By establishing these clear guidelines for which mail servers are permitted to send messages for a given domain, SPF significantly reduces the chances of successful email spoofing, where attackers attempt to impersonate a legitimate sender.