DKIM (DomainKeys Identified Mail) is an email authentication method that adds a digital signature to outgoing emails, allowing receivers to verify the email has not been altered.

What is a DKIM selector?

A DKIM selector is a name used to look up the DKIM public key in DNS. Different email providers use different selectors (e.g., "google" for G Suite, "k1" for Mailchimp).

DKIM Record Lookup

Enter a domain and DKIM selector to verify your DKIM email authentication records.

Domain Name

Selector

Server processing — your query is handled securely on our servers.

How to use DKIM Record Lookup

The DKIM Lookup retrieves the DomainKeys Identified Mail public key published at a given selector for a domain, letting you confirm your DKIM signing is set up correctly. DKIM lets a sending server cryptographically sign outgoing mail so receivers can verify it really came from your domain and was not altered in transit — a cornerstone of modern email authentication alongside SPF and DMARC. Use this tool to check that a selector’s public key exists and is well-formed, to debug failing signatures, or to confirm a new key has propagated before switching to it.

Enter the domain and the DKIM selector to look up.
Click Lookup to fetch the published TXT record.
Confirm a valid public key (p=) is present.
Check the key type and any flags in the record.
Verify the selector matches the one your mail server signs with.

Selectors and how DKIM verification works

When a server signs a message it adds a DKIM-Signature header naming the domain and a selector. The receiver looks up the public key at selector._domainkey.domain, then uses it to verify the signature against the message body and signed headers. A selector lets one domain publish several keys — for different providers or for rotation — so naming the right selector is essential. If the key is missing, malformed, or does not match the private key used to sign, verification fails and the message loses an authentication pass.

DKIM record tags
Tag	Meaning
v=DKIM1	Record version
k=rsa	Key type
p=	The Base64 public key (empty means revoked)

Rotating keys and common pitfalls

Good practice rotates DKIM keys periodically, which is exactly why selectors exist: publish a new key under a new selector, switch signing to it, then retire the old one once no in-flight mail still references it. A frequent mistake is a key truncated by a DNS provider’s record-length limits, leaving an invalid public key; another is publishing the key under the wrong selector so the receiver cannot find it. This lookup surfaces both problems immediately by showing exactly what is published where.

Glossary

DKIM: DomainKeys Identified Mail — a method of signing email to prove authenticity.
Selector: A label naming which DKIM key to use, queried as selector._domainkey.domain.
Public key (p=): The key receivers use to verify a DKIM signature.
Key rotation: Periodically replacing signing keys for security.
DKIM-Signature: The email header carrying the signature and selector.

Frequently Asked Questions

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Why use DKIM Record Lookup?

Real-time DNS lookups using live resolver queries
Supports IPv4 and IPv6 addresses
No software to install — runs entirely in the browser
Results include TTL values and record priority

Common use cases

Verify DNS propagation after updating nameservers
Check MX records when troubleshooting email delivery
Look up SPF/DKIM/DMARC records for email security audits
Test whether a SSL certificate is valid and up to date
Find the IP address behind a domain name

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