DKIM Record Checker
DKIM signs outgoing emails. Receivers verify the signature using a public key in DNS.
DKIM lives on <selector>._domainkey.<domain>. If selector is empty, we try common ones.
Result for blackboard.com
Found
Selector: selector1
(TXT on selector1._domainkey.blackboard.com)
v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAtN6F7Eacqn/+LW9ziUE95F03ESMnwbFYAKyASQZtTYpscr2u2MfviCLpg+u67ndi73wQgOrP5FXkDQOyOrbtOEf075Oo3UjdU5gVk4ZDluMBtk0iFm0NuoYVemLK82dqsAROTFPj3d9w6I2Xcz1Btw3gnpDXva/Vm67PU5F+J7dz5EXlBFsgXAdsnfj1jaqTzlKZCxyn+mpTMkMQ3A6whe34PtxgrmOawtUt8w+R2oaOCrg/J8jpxpaffEi6xxvhwBnlugPeaGsaknDXv3LGTWvgGfVANg8ONkSpbPXLQOPh0vLVgGSqq5/1eOy2+kVYwJAgbpigijB+hMRUqYjEgQIDAQAB;
Selector: selector2
(TXT on selector2._domainkey.blackboard.com)
v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAv2HbDHzt/VI7qfDWNBipMO+RozpVSE163N2EEJRb8wxFgKX/oRA3d87gxJUMCzW/0WxFZLQUB+7aqR/ghmqtqy7aagVDwT3vRtwtDe1o0OYoOnyIMn0gubKZz9CwJZwEoqy/JtFWdotnJWFF6luIQav+Nv7HUpnPHjF3W6KNxd13tLpNfyy1x70zG8rjDmOpAklFvUtcPpl7Rqt+G/ATNd2+FdDpceleqPNWC1Di3hxV3m0XMxv69TACB8s4OZCSKwbytSaInB/+hR2SwAjfc9qBsRoG8AvsEYFv4M65rn1ChFoSXvQURN8nh7M3qRB/y+33FzDHBcM/JzPfe5639QIDAQAB;
FAQ
Why does DKIM require a selector?
Selectors allow rotating keys and running multiple keys per domain.
Where is DKIM published?
TXT on <selector>._domainkey.<domain>.
DKIM record exists but emails still fail DKIM?
Signing may be disabled or the selector used in email differs from DNS.
Do I need DKIM if I have SPF?
Yes, many providers use both for best deliverability and DMARC alignment.
Can I have multiple DKIM selectors?
Yes, that is common for key rotation or multiple senders.
What is DKIM?
DKIM (DomainKeys Identified Mail) adds a cryptographic signature to outgoing emails. DNS stores a public key that allows receivers to verify authenticity.
Example
v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0B...
Common mistakes
- Wrong selector (the record exists but under a different selector).
- Key is split incorrectly across multiple TXT chunks (some DNS UIs break it).
- Publishing DKIM but not enabling signing on the mail provider.