Free tools, sorted by what you are trying to do.

Paste or upload an aggregate report and get total volume, pass and fail rates, and which senders are failing — parsed locally, never uploaded.

Builds a valid DMARC record from your choices — policy, reporting addresses, percentage and the advanced tags most guides skip.

Assembles an SPF record from the services you send with, and counts DNS lookups against the limit of ten as you add them.

Generates a DKIM key pair with your browser's WebCrypto and builds the TXT record to publish. The private key never leaves your device.

Builds the _mta-sts record and the mta-sts.txt policy file together, with MX wildcards and max_age checked before you publish.

Builds the _smtp._tls record that asks senders to report failed TLS connections, with each email or https destination checked.

Reads the SPF record, walks every include and redirect, and counts DNS lookups against the limit of 10.

Reads your SPF, DKIM, DMARC and MTA-STS configuration in one pass and tells you which are missing or weak.

Pulls one domain’s DMARC record and explains every tag — policy, alignment, reporting addresses and subdomain coverage.

Checks a DKIM record by selector and reports key type, key size and each tag, with quick-picks for the common providers.

Checks the MTA-STS policy record and the TLS-RPT address together — the pair that forces inbound mail over TLS and reports when it fails.

Looks up the BIMI record, previews the logo, and confirms the VMC and the DMARC enforcement level BIMI requires before it will display.