DKIM (DomainKeys Identified Mail)  is one of the ways to protect emails from spoofing and works together with other protections like SPF and DMARC. Using a digital signature, DKIM verifies that the email content wasn’t changed after sending and that it truly comes from the stated sender.

What DKIM means for everyday users (email recipients)

• DKIM adds a cryptographic signature to the email to confirm the message hasn’t been altered and is authentic.
• Just like SPF, even if an email passes DKIM checks, it doesn’t always mean it’s safe—stay cautious.
• If an email fails DKIM checks on your mail server, it’s typically marked as suspicious or rejected.

What DKIM means for businesses and IT admins (protecting your sending domain)

• DKIM lets the sender attach a digital signature created with a private key, which can be verified using a public key published in DNS.
• This ensures the email wasn’t modified in transit and truly originates from the claimed domain.
• DKIM is used alongside SPF and DMARC to minimize domain abuse for phishing or spoofed emails.
• DKIM helps recipients distinguish legitimate emails from fakes by validating message integrity and authenticity.