Datos clave
DKIM is a public key in DNS at selector._domainkey.domain that receivers use to verify a message signature. Enter the domain and the selector (it is in the DKIM-Signature header as s=…) or leave it blank and we try 30 common selectors. An RSA 2048-bit key is considered good, under 1024 weak.
- Precio
- Gratis
- Registro
- No necesario
- Procesamiento
- On our server: DNS TXT (and CNAME) queries to selector._domainkey.your-domain, tag parsing and a key-length calculation
- Entrada
- A domain and, optionally, a selector (or paste selector._domainkey.domain in full)
- Límites
- No sign-up; 12 checks per minute per IP, no daily limit. Without a selector, 30 common ones are tried within about 10 seconds
- Resultado
- For each selector found: the record, version and key type, RSA key length, flags (such as testing mode) and warnings; a warning for a dangling CNAME
- Última actualización
Código abierto en GitHub
Ejecuta la misma comprobación en tu propio equipo: una herramienta de línea de comandos de Node.js, una biblioteca y una GitHub Action. Código abierto con licencia MIT.
DKIM record lookup and key check
DKIM signs every message with a domain key, and the receiver verifies the signature against the public key in DNS at selector._domainkey.domain. This tool finds that record for your selector or tries 30 common ones (Google Workspace, Microsoft 365, Mailchimp, SendGrid, Zoho, Fastmail, Proton, HubSpot and more), follows CNAMEs, parses the tags and measures the RSA key length. Selectors cannot be listed via DNS, so "not found" only means "not among the selectors checked".
Cómo usar
- Enter the domain; take the selector from the DKIM-Signature header (s=) if you have it
- Without one we try 30 common selectors — it takes a few seconds
- Check the key status and replace keys shorter than 2048 bits
FAQ
PromoPilot frente a alternativas: comparación
Comparamos solo lo que está confirmado en las páginas de cada servicio. Donde no pudimos confirmar un dato, la celda muestra "—".
| Parámetro | PromoPilot | MxToolbox DKIM Lookup | dmarcian DKIM Inspector |
|---|---|---|---|
| Looks up a given selector | ✓ | ✓ domain:selector or the full selector._domainkey.domain host name | ✓ domain and selector required |
| Tries common selectors with no input | ✓ 30 selectors | Not stated on the page | ✗ |
| Key length and warnings | ✓ | The result format is not described on the page | ✓ tag table, warnings/errors and public key length |
| No sign-up needed | ✓ | — | ✓ a free tool; entered data is not stored (per the site) |
Desplaza la tabla hacia los lados
Dónde somos más débiles: a real message’s signature is not verified, the scan is limited to 30 common selectors and 10 seconds, and there is no alignment check or combined SPF/DMARC report on the same page.
Cuándo elegir PromoPilot: When you need to find a domain’s DKIM key or check length and syntax after setting up a mail service. We do not verify the signature of a specific message, and a blind scan may miss a non-standard selector.
Comprobado el: . "—" significa que no está confirmado en la página oficial; las condiciones y los precios cambian, así que consulta los sitios de cada servicio.