DKIM (DomainKeys Identified Mail)
What is DKIM?
DKIM (DomainKeys Identified Mail) signs outgoing emails with a private key. The matching public key is published in your domain’s DNS. Receiving servers use it to confirm the email was sent by an authorised server for your domain and was not changed in transit.
Your email provider generates the keys; you publish the DNS record it gives you.
Why DKIM matters
DKIM is one of the three standard email authentication checks, with SPF and DMARC. Authenticated mail is trusted more and lands in the inbox more often.
Related marketing terms
An SPF record is a DNS entry listing which servers may send email for your domain, so receivers can reject forged messages.
DMARC is a DNS policy telling receivers what to do with email that fails SPF or DKIM for your domain, and where to send reports.
Email deliverability is how reliably your emails reach the inbox rather than spam, shaped by authentication, reputation and content.