Symptom: CNAME records for sending sit unverified indefinitely on Cloudflare despite correct values.
1. Confirm the cause: in the Cloudflare DNS panel, look at the proxy status icon next to each Resend CNAME. An orange cloud means the record is proxied; proxied records do not resolve as CNAMEs, so verification can never complete no matter how long you wait.
2. Fix: click each icon to switch it to gray, i.e. DNS only. Do this for every Resend CNAME record, including the rsend one if shown.
3. Keep them DNS only permanently: re-enabling the proxy later breaks verification again.
4. Verify: use the "Restart verification" button in the Resend dashboard and confirm the CNAMEs verify. Also confirm with nslookup -type=CNAME on the record name that it resolves to the Resend host rather than Cloudflare addresses.