Business email depends on trust. Receiving servers need a reliable way to check whether a message claiming to come from your domain is legitimate. SPF, DKIM, and DMARC work together to provide that signal.
SPF defines approved senders
An SPF record lists the services allowed to send mail for a domain. Keep the record accurate and avoid exceeding lookup limits as tools are added.
DKIM proves message integrity
DKIM adds a cryptographic signature to outgoing email. The receiving service checks that signature against a public key in DNS and can detect changes made in transit.
DMARC turns signals into policy
DMARC tells receiving servers what to do when SPF or DKIM checks fail. Begin with reporting, review legitimate senders, and move toward enforcement with evidence rather than guesswork.
Together, these controls improve visibility, reduce spoofing risk, and support more dependable delivery.