Klaviyo & Email
DKIM (DomainKeys Identified Mail)
Quick definition
A cryptographic signature added to email headers that proves the message was sent by an authorized server. Required for deliverability.
What it actually means
DKIM adds a public-key signature to outgoing emails; inbox providers verify it against your DNS-published public key. Combined with SPF and DMARC, DKIM authenticates that the email is genuinely from your domain. Klaviyo requires DKIM setup for any branded sending domain. Without it, sends fall back to klaviyomail.com and inherit a shared sender reputation — measurably worse deliverability than a properly authenticated branded sender.
Related terms
Email Deliverability
The probability that your email reaches the inbox instead of spam or the promotions tab. Driven by sender reputation, authentication, and engagement.
SPF (Sender Policy Framework)
A DNS record that authorizes which servers are allowed to send email on behalf of your domain. Required for deliverability.
DMARC
A DNS policy telling inbox providers what to do if a message fails SPF or DKIM checks (reject, quarantine, monitor).