DKIM (DomainKeys Identified Mail)
A cryptographic signature your mail server adds to outgoing email, proving the message wasn't altered and really came from your domain.
Free · no signup · last reviewed August 29, 2026
The definition
A cryptographic signature your mail server adds to outgoing email, proving the message wasn't altered and really came from your domain.
Why it matters to an owner
One of the three records (with SPF and DMARC) that decide whether your invoices land in inboxes or spam.
Keep going
SPF (Sender Policy Framework)A DNS record listing which servers may send email for your domain. Receiving servers check…DMARCThe policy record that tells receiving servers what to do when SPF/DKIM checks fail: monit…SPF, DKIM & DMARC in Plain EnglishThe three DNS records that make your email believable — what each does, the classic mistak…
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