SPF, DKIM & DMARC for iCloud Mail

SPF & DKIM — get both from your Apple ID's iCloud+ settings

Apple ID account settings → iCloud+ → Custom Email Domain (add or select your domain). Apple shows you a bundle of DNS records to add in one go, including an SPF record and a DKIM record under the selector sig1. Copy those exactly as shown rather than from a guide — the DKIM value is unique to your account and Apple signs your mail with its own key, not one you generate yourself. A key pair from our generator would never actually get used to sign anything.

DMARC

Not specific to iCloud Mail — the same record works everywhere. Use the DMARC record generator to build yours.