Why is domain setup critical for cold email?

Cold email starts with zero relationship trust. Without proper domain setup, you're adding technical trust failures to that already challenging position.

Authentication signals: SPF, DKIM, and DMARC tell mailbox providers that messages actually came from authorized senders. Missing authentication means failing checks that legitimate senders pass routinely.

Domain age: Brand new domains have no history. Mailbox providers treat them with more suspicion than established domains. Setup should happen well before sending begins.

DNS configuration: Proper MX records, reverse DNS (PTR records), and correctly formatted authentication records signal professionalism. Misconfigurations suggest either technical incompetence or intentional evasion.

Warmup foundation: A properly configured domain can build reputation through warmup. A misconfigured domain accumulates problems that compound over time.

Technical setup doesn't make cold email welcome, but it removes objections that would otherwise guarantee filtering. You cannot sail into harbor without proper documentation, no matter how valuable your cargo.