Email authentication
What is DMARC?
How a domain tells receiving mail systems what to do when authentication fails.
Resources
Understand the protection before the acronyms.
Short, accurate guides to the standards and risks behind business email identity.
Email authentication
What is SPF?
A plain-language guide to the systems allowed to send for a domain.
Email authentication
What is DKIM?
How legitimate email carries a signature that receiving systems can verify.
DMARC policy
What does p=none mean?
Why a monitoring policy is useful—and why it is not the finish line.
DMARC policy
DMARC quarantine vs reject
The practical difference between the two enforcement policies.
Domain abuse
What is email spoofing?
Why a message can appear to come from a business that did not send it.
Impersonation
What is a lookalike domain?
How small changes to a domain can create a convincing false identity.
Brand trust
What is BIMI?
How strong authentication can support a verified brand presentation in participating inboxes.
Transport security
What is MTA-STS?
How domains can ask sending mail systems to require a secure delivery path.