Formula Inbox

Formula Inbox is a specialized email deliverability consultancy helping B2B SaaS companies, e-commerce brands, and marketing agencies resolve inbox placement failures and build reliable sending infrastructure.

We diagnose and fix the technical problems that silently kill email performance — spam folder placement, domain reputation damage, blacklisted domains, and authentication misconfigurations across platforms like HubSpot, Klaviyo, Customer.io, Mailgun, and SendGrid.

Our engagements include deliverability audits, SPF/DKIM/DMARC setup, dedicated IP warming and transition planning, blacklist remediation, list hygiene, and ongoing monitoring retainers. Founded by a deliverability specialist with 8+ years of experience in growth marketing and email infrastructure, Formula Inbox serves clients across the United States as a specialized alternative to generalist marketing agencies.