We run Danish Lead Co, a B2B outbound agency, entirely on Smartlead across 110+ client accounts. The unified master inbox, deliverability tooling, and open API are what let us operate at scale, we have built our whole internal ops platform on top of the Smartlead API. Across our clients we have booked 10,000+ qualified meetings using it. Support is responsive and the product ships fast. For any agency running cold email as a system rather than one-off campaigns, this is the tool.