Source: https://uptimeify.io/resources/platform-and-support/glossary/dkim

# DKIM (DomainKeys Identified Mail)

> DKIM (DomainKeys Identified Mail) adds a cryptographic signature to outgoing email so receivers can verify it really came from your domain and was not altered.

The signature is checked against a public key published in your DNS. Valid DKIM proves authenticity and integrity; broken or missing DKIM hurts deliverability. Together with SPF and DMARC it forms modern email authentication.