Symptom: domain status reads partially_verified instead of verified.
1. Confirm the cause: this status applies to domains created after August 2026 that show two CNAME records. Each CNAME is verified on its own, so one can pass while the other fails.
2. Note what still works: you can send mail while partially verified, but you have no fallback sending server, so treat it as degraded, not done.
3. Fix: open the domain details page and find which of the two CNAMEs is flagged. Correct only that record at your DNS provider, copying the exact name and value from Resend.
4. Check the usual CNAME traps for the failing one: it must not be proxied (Cloudflare orange cloud), and no other record type may exist on the same subdomain (a CNAME cannot co-exist with A, TXT, or MX records there).
5. Verify: hit "Restart verification" and confirm the status moves to verified. If the failing CNAME sits on a subdomain you cannot clear, configure a different Return-Path subdomain and use the records Resend generates for it.