Announcing PostaSend 2.0: Multi-tenant Isolation and Dedicated IP Pools

When we launched PostaSend 18 months ago, we built it to solve a specific problem: developers integrating transactional email into their SaaS products were spending too much time managing provider credentials, debugging deliverability issues, and stitching together webhooks. The response exceeded every projection — teams adopted PostaSend faster than we anticipated, and their feedback pointed us clearly toward the next set of problems to solve.

The most common request from growth-stage SaaS teams was native multi-tenant support. Building on PostaSend's existing tenant primitive, version 2.0 ships a full isolation model: separate sending identities, suppression lists, quota tracking, and analytics per tenant, all manageable via API or the new dashboard. A SaaS product with 500 customers can now create 500 isolated PostaSend tenants, each with their own API key, domain, and event stream, with no cross-tenant leakage.

The second major addition is dedicated IP pool management for Enterprise accounts. IP reputation is one of the most opaque aspects of email deliverability — when you share an IP with thousands of other senders, your inbox placement is influenced by their sending behavior. With dedicated IP pools, Enterprise customers get IPs assigned exclusively to their account. PostaSend handles the warming schedule automatically, using a configurable ramp-up curve to gradually increase volume while monitoring reputation signals from Gmail Postmaster Tools and Microsoft SNDS.

Alongside these core features, 2.0 ships a redesigned analytics dashboard with cohort-based open and click rate analysis, a new template editor with real-time variable preview, and an overhauled webhook debugger that shows the full request/response cycle for each delivery event. The SDK is updated to v2 with breaking changes — see the migration guide at docs.postasend.dev/migrate-v2 — but existing v1 API keys continue to work until December 2025.