About this tool
Inspect DKIM selector records before connecting a mail provider, rotating keys, or enforcing DMARC so signing keys and testing flags are visible in one report.
DKIM Record Checker inspects the selector TXT record that publishes a domain's email signing public key. It builds the selector._domainkey hostname, reads the DKIM record, parses key tags, and highlights missing keys, duplicate selector records, testing flags, and unusual key settings.
- Builds the selector._domainkey hostname and looks up DKIM TXT records.
- Parses v, k, p, t, h, s, and n tags into a readable selector report.
- Flags missing public keys, duplicate selector records, testing flags, unusual key types, and short-looking keys.
How to use DKIM Checker
Enter the sending domain and selector supplied by your mail provider, then run the check. Review the lookup hostname, public key presence, key type, testing flag, and service or hash restrictions before updating DNS, rotating a key, or enabling DMARC enforcement.
When this tool is useful
- Verify a new mail provider's DKIM selector before sending production email.
- Check selector records during key rotation, provider migration, or DNS cleanup.
- Audit DKIM alongside SPF and DMARC when deliverability or spoofing reports appear.
Practical tips
- Use the exact selector from your mail provider; common examples include default, google, selector1, and s1.
- Keep one DKIM TXT record per selector hostname so receivers do not encounter ambiguous keys.
- Remove t=y testing flags after production signing is validated.
Examples you can test
These examples show the kind of real input and reviewed output this tool is designed to support. Use them as a starting point before pasting your own production content, then compare the output with the destination system that will use the result. The goal is not only to produce a value, but to make the input assumptions, output format, and review step clear enough that the result can be trusted in a real workflow.
Check a provider selector
Example input
example.com with selector default
Expected output
DKIM lookup hostname, public key status, key type, and warnings
Useful when a mail provider asks you to publish a DKIM TXT record.
Review key rotation
Example input
example.com with selector selector1
Expected output
Parsed DKIM tags and testing flag status
Selector checks help confirm a new key is live before old signing keys are removed.
Validation checklist
Run through these checks before copying the result into a CMS, codebase, spreadsheet, campaign, support ticket, or production document. Small formatting differences, unit assumptions, hidden whitespace, and platform-specific rules are common sources of mistakes in quick browser tools, so the final review should happen in the same context where the output will be used.
- Use the exact selector supplied by the sending provider.
- Confirm the p public key tag is present and not truncated.
- Keep exactly one DKIM TXT record per selector hostname.
- Remove t=y testing flags after production signing is confirmed.
- Pair DKIM checks with SPF and DMARC before strict DMARC enforcement.
Why people use this tool
DKIM helps receivers verify that a message was signed by an authorized domain and was not changed in transit. If the selector record is missing, truncated, or left in testing mode, SPF and DMARC work can still fail because aligned DKIM signatures cannot validate.
Related search intents
dkim record checker, dkim checker, dkim lookup, check dkim record, dkim selector checker.