Patent attributes
Sender Policy Framework (SPF) is one of the most widely used methods of distinguishing electronic mail that is authorized by the purported sending domain from unauthorized mail. SPF policies are published into a domain's DNS and then looked up and evaluated by mail receivers. Due to the complexity and limitations of the SPF specification, implementation mistakes are widespread. This problem is compounded by the common practice of nesting SPF policies which introduces hidden risks, particularly exceeding DNS lookup limits. To address these issues, inline service provider designation may be configured to capture the benefits of existing techniques without their associated costs. Additionally, the domain owner may enjoy simplified SPF service provider onboarding and policy failover redundancy to protect against SPF service provider disruptions, thus improving policy availability uptime.
