Troubleshooting
Specific failures, with the causes ordered by how often they're it.
- Troubleshooting
Why DKIM verification fails (and how to fix each cause)
The concrete reasons a DKIM check fails after you've published the key: selector mismatch, a truncated public key, DNS flattening, and message modification in transit.
Unitpost · July 27, 2026
- Troubleshooting
How to fix an SPF record that isn't found
Why an SPF lookup returns nothing even after you've added the record, and how to diagnose it: propagation, wrong host, quoting, and the one-SPF-record rule.
Unitpost · July 27, 2026
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