Deliverability

Also known as: email deliverability, inbox placement

Deliverability is the rate at which sent emails reach the recipient's inbox rather than the spam folder, promotions tab, or being silently dropped by the inbox provider. Deliverability depends on sender reputation (domain age, complaint rate, bounce rate), authentication (SPF, DKIM, DMARC), content (spam-triggering language), and engagement (open and reply rates from past sends).

Deliverability is not a number you can read from your email-sending tool — that tool only knows whether the email left its system, not whether it reached the inbox. Real deliverability measurement requires inbox-placement tests against actual seed accounts at Gmail, Outlook, Yahoo, etc.

The single biggest deliverability mistake is sending volume too soon on a cold domain. Warming up (4-6 weeks of low-volume legitimate-looking traffic) before any cold outbound is the only reliable way to build sender reputation. Skip warmup and your first 1,000 cold emails train Gmail to treat your domain as spam.