SPF and DMARC records are a single line syntax with no system feedback. One incorrect tag and your domain either bans real emails or allows spamming. Typical discovery is post damage.
Techisane's DMARC / SPF Explainer demonstrates what your record does. Copy DMARC or SPF DNS record and get a breakdown in plain English with the tag-by-tag analysis; plus a check for the misconfigurations that break authentication in production.
Paste a DMARC or SPF TXT record below (find it by running a DNS TXT lookup on your domain, or on _dmarc.yourdomain.com for DMARC). This runs entirely in your browser - nothing is sent anywhere.
This is a plain-English explanation and basic misconfiguration check, not a full DNS audit - for a complete health check, cross-verify with your DNS provider or a dedicated mail-auth testing tool.