SPF, DKIM, and DMARC are DNS-based email authentication tools. They help receiving mail servers decide whether messages claiming to be from your domain are legitimate.
SPF
SPF lists the systems allowed to send email for your domain.
DKIM
DKIM adds a cryptographic signature to outgoing mail. The public key is published in DNS.
DMARC
DMARC tells receiving systems what to do when SPF or DKIM checks fail. It can also send reports to help you understand who is sending mail for the domain.
Why It Matters
These records improve trust and reduce spoofing. They are especially important for invoices, password resets, and customer communications.
Set them carefully, especially if several services send mail for the same domain.
