Warmupinbox

Warmup Inbox is a focused deliverability infrastructure tool — if your SDR or BDR team is burning through domains or watching reply rates drop, this is the kind of unglamorous fix that actually moves the number. On the agentic readiness front, the API is available and rated Capable, meaning you can wrap it into your own orchestration layer or MCP setup without too much friction — it won't fight you, but you'll need to build the scaffolding yourself since native MCP status is unconfirmed. Pricing starts at $15/month per inbox on the low end but scales per-inbox across a fleet of sending domains, which means enterprise teams managing 20+ inboxes should run the math carefully before assuming this is cheap. The honest limitation is scope: this tool handles warming and health monitoring, but it doesn't replace a sequencer or a sending platform — you're buying one layer of the stack, not the whole stack.