Why DKIM Fails and How to Fix It

DKIM fails when the receiving server cannot verify the DKIM signature using the public key published in DNS. This reduces trust and can hurt deliverability.

Common Causes

Wrong selector (example: using default while the provider uses google)
Missing DKIM TXT record
Public key formatting issues (broken quotes, spaces, missing p=)
Outbound DKIM signing is disabled
Email modified in transit (some gateways change headers/body)

How to Fix DKIM

Verify the correct selector used by your mail provider
Publish the DKIM TXT record at: <selector>._domainkey.<domain>
Ensure the record contains a valid public key (p=)
Enable DKIM signing on the outbound server/provider

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