Setting up email authentication for Kit (ConvertKit)

Kit (formerly ConvertKit) sends with a kit.com return-path until you verify your sending domain — two CNAMEs that move the machine-visible address onto your own domain.

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The one-paragraph version

Kit (formerly ConvertKit) needs just two CNAMEs — ckespa handles SPF and the return-path, and cka._domainkey handles DKIM. Until you verify, your return-path is a kit.com address; verifying puts your own domain in the machine-visible return-path so DMARC aligns. Expect open rates to wobble for two to three weeks afterward while mailbox providers recompute your reputation. Source: help.kit.com · verified 2026-07-15

The full checklist

Step 1. Complete domain authentication inside the service (see above) and paste the DNS records it generates.
Step 2. Make sure your SPF record includes this service — and count your lookups: the limit is 10 and every service adds some.
Step 3. Publish DMARC with p=none and a rua address, watch reports for a week, confirm this sender shows 100% pass.
Step 4. Only then tighten the policy — quarantine, then reject.

Frequently asked

Will this change break my current sending?

No. Adding SPF includes and DKIM records only adds authentication — it never blocks existing mail. The only risky step is tightening your DMARC policy, and that comes later, after reports confirm everything passes.

How do I know it worked?

Send yourself a test email and inspect the headers for spf=pass, dkim=pass and dmarc=pass — or just watch your DMARCKeeper dashboard: the sender's pass rate should hit 100% within a day or two.

Do I still need DMARC if SPF and DKIM are set up?

Yes. SPF and DKIM authenticate mail; DMARC is what tells receivers to BLOCK mail that fails, and it's the piece Gmail, Yahoo and Outlook now check for explicitly.

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