Email authentication proves that messages are legitimately sent from your domain and helps prevent spoofing. Learn SPF, DKIM, DMARC, and why they matter for deliverability.
Email authentication is a set of standards that help receiving mail servers verify that an email claiming to come from your domain is legitimate. The most common mechanisms are SPF (authorized senders), DKIM (cryptographic signature), and DMARC (policy and reporting).
Authentication improves deliverability because providers can trust that your domain is not being spoofed. It also protects recipients by reducing phishing and fraudulent messages that impersonate your brand.
A strong setup usually includes SPF and DKIM for all sending systems and a DMARC policy that starts with monitoring (p=none) and gradually enforces protection (quarantine or reject). Ongoing maintenance matters too, especially if you add new sending services or change providers.