Cold Email Deliverability

Cold email deliverability is the operating constraint that decides whether outbound exists or does not. A campaign with a 4% reply rate on the surface produces zero meetings if 90% of the emails landed in spam. Deliverability is the gate. Everything else (research quality, personalization, sequence design) only matters if the email crosses the inbox boundary. The discipline covers five layers: sender authentication (SPF, DKIM, DMARC), domain reputation, sending volume per inbox per day, content patterns that trigger filters, and spam-trap exposure from low-quality lists.

The default failure mode for funded teams is sending too much from one domain too fast. A startup spins up sales@company.com on day one, sends 500 emails in week one, and the primary domain reputation is destroyed by week two. Recovery takes 90 days minimum and the marketing emails get caught in the blast radius. The correct architecture uses secondary sending domains (sales-company.com, get-company.com), warmed gradually over 30 days, with strict daily volume caps per inbox, while the primary domain is never used for cold outbound at all. This is invisible to the prospect because the from-name still reads as your team.

Inside the AI Sales Department, deliverability is treated as an operating constraint, not a setting. Every inbox runs against a daily cap. Spam-trap monitoring runs continuously. If reply rate or bounce rate slips, the sequence pauses automatically until the cause is identified. We never use the primary domain for cold outbound. Your marketing emails and your transactional emails stay clean because the cold motion is fully isolated. See AI SDR for how the agent handles volume management against these constraints.