SPF / DKIM / DMARC checker & record generator

Check a domain's email authentication (SPF, DKIM, DMARC) from your browser and generate SPF and DMARC records.

DNS lookups go from your browser to Google Public DNS (dns.google) or Cloudflare (cloudflare-dns.com), not to this site.

Check

Domain (e.g. example.com) DKIM selector (optional)

Record generator

Sending services in use

Trailing mechanism DMARC report address (rua)

SPF record DMARC record

Rollout: start with p=none for 2-4 weeks while reading reports, then p=quarantine (pct=10 rising to 100), then p=reject. The rua mailbox receives XML aggregate reports.

Where to set DNS records (confirm the current menu names on each host's help page)

・Xserver サーバーパネル DNSレコード設定
・さくら会員メニュードメイン/DNS
・ロリポップユーザー専用ページ独自ドメイン設定
・お名前.com Navi DNS設定
・ムームーDNS
・Cloudflare DNS
・Amazon Route 53
・Squarespace Domains (旧 Google Domains)

Gmail requirements: all senders need SPF or DKIM. Bulk senders (5,000+/day to Gmail) need SPF and DKIM and DMARC with alignment, one-click unsubscribe, and a spam rate under 0.3%. PTR and the actual sending IP cannot be checked from the browser; confirm with a test message to Gmail and 'Show original' (Authentication-Results), plus Google Postmaster Tools.