DKIM
DomainKeys Identified Mail, commonly known by the acronym DKIM, is an email authentication protocol developed to identify spoofing and impersonation. It does this by signing every outgoing email message. The public signing key is published in the Domain Name System (DNS).
On this page
Source content checked . English translation published 2026-10-27.
In business automation
DKIM signs an email message with a key that the recipient can check in DNS. In automation, alongside SPF, it helps show that a message came from your system and was not changed in transit.
Examples
These examples illustrate a possible workflow. Adapt the connections and rules to your own systems.
Sign an order follow-up email
After the shipping step, an email is sent to the customer. The server signs the message, and the public key is stored in DNS. The receiving server checks the signature. A change to the subject or body in transit breaks the signature and the message is flagged as suspicious.
Relevant tools
- Resend
- Domain verification includes a DKIM record. Check that signing is active before sending operational emails to customers.
What to check
- A signature without domain alignment between the From domain and the signing domain can still look suspicious.