Does my hostname need to match my rDNS lookup? (Forward-confirmed reverse DNS - FCrDNS)

• FCrDNS (Forward-confirmed reverse DNS) means:
• IP → PTR → hostname → A → same IP
• The reverse lookup gives a hostname. Forward lookup of that hostname returns the original IP. The loop completes.
• Why it matters:

• Proves consistent configuration
• Prevents spoofed PTR records
• Major trust signal for receivers

Example:

• 192.0.2.1 PTR mail.tidalmail.com (reverse)
• mail.tidalmail.com A 192.0.2.1 (forward)
• Both match = FCrDNS passes.

Many receivers require FCrDNS for bulk senders. Mismatch causes deferrals or rejections.

The registry confirms the ship name matches the hull number, and the hull number matches the ship name. No discrepancies.