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DKIM checker
Enter a domain and selector — we find the DKIM key, estimate its length and flag problems. Free, no signup.
FAQ
Where do I find the DKIM selector?
In the DKIM-Signature header of any message — the s= parameter. Or in your email provider settings; Sendersy shows it on the domain page.
How long should the key be?
2048 bits is the standard. 1024 still works but is weak. Gmail rejects keys shorter than 1024.
Why DKIM if I have SPF?
SPF breaks on forwarding, DKIM does not — the signature travels with the message. DMARC and inbox placement need both.