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Free Email Security Tool
Validate your DomainKeys Identified Mail signatures. We scan 50+ common selectors automatically and flag misconfigurations that could hurt deliverability.
Free forever · No account needed · 50+ selectors scanned
A silent SPF or DKIM change can quietly send your emails to spam for weeks before anyone notices. Drop your email and we'll alert you the moment something looks off, so you fix it in minutes, not after a deliverability cliff.
Check every aspect of your email infrastructure
Mailsoftly handles SPF, DKIM & DMARC automatically. Campaigns, automation, and analytics in one place.
Free to start with your Google Workspace account. No credit card required.
This free DKIM checker scans more than 50 common DKIM selectors for any domain, including the ones used by Google Workspace, Microsoft 365, Mailchimp, SendGrid, Constant Contact, Klaviyo and Zoho. DKIM adds a cryptographic signature to every email you send, and receiving servers verify it against the public key you publish in DNS at selector._domainkey.yourdomain.com. If the scan finds a selector, your DKIM key is live and mail signed with it can be verified. If nothing is found, your domain is either not signing mail or uses a custom selector name.
Open any message you have sent and view its raw headers: the DKIM-Signature header contains an s= tag, and that value is your selector. If you cannot access the headers, run the scan above, which automatically tests more than 50 selector names used by the major email providers and ESPs. Your DKIM record lives in DNS at selector._domainkey.yourdomain.com as a TXT record containing the public key.
