What you enter is sent to cloudflare-dns.com, dns.google. Requests only happen when you ask for them.
Email Diagnostics
Check MX records, SPF, DKIM, and DMARC configurations
Check MX records, SPF, DKIM, and DMARC configuration for any domain
The authentication score, MX records, SPF, DKIM and DMARC appear here. Nothing is looked up until you run the diagnostics.
What is checked:
Learn more about email authentication at dmarc.org