High-Deliverability SMTP Server Setup

I need a self-hosted SMTP environment that can reliably push up to 10,000 messages a day straight into Gmail, Outlook, and Yahoo inboxes. The core objective is a rock-solid sender reputation, minimal spam-folder drift, and the flexibility to scale further once the infrastructure proves itself... (Budget: $250 - $750 USD, Jobs: Bulk Marketing, DNS, Email Marketing, Interspire, Linux, Postfix, SMTP)