dmark / Guides
Email security guides
Pick the guide for your email provider, or read what SPF, DKIM and DMARC actually do. To see where your domain stands right now, start with a free check.
By email provider
- DMARC, SPF and DKIM for Microsoft 365Exact DNS records and steps to protect a Microsoft 365 domain from email spoofing. Free check at dmark.is.
- DMARC, SPF and DKIM for Google WorkspaceExact DNS records and steps to protect a Google Workspace (Gmail) domain from email spoofing. Free check at dmark.is.
- Lock down a domain that doesn't send emailUnused domains are popular with scammers. Two DNS records stop anyone sending email as the domain. Free check at dmark.is.
What the terms mean
- What is DMARC?DMARC tells mail servers what to do with fake email sent in your domain's name. How it works, which policy to pick and how to start.
- What is SPF?SPF is the list of servers allowed to send email as your domain. What the record looks like, the rules that matter and the most common mistakes.
- What is DKIM?DKIM adds a digital signature to email so receivers can tell it came from you. How it works and where to get the key.