The Play
Inboxes that actually land.
Most cold email failures are deliverability failures. We build the mailbox manager that watches every domain, warms what's cold, heals what's burned, and only sends from inboxes that are landing in the primary tab.
What it is.
A mailbox manager is the control plane above Smartlead, Instantly, and Lemlist. It inventories every mailbox and domain, runs daily deliverability checks, orchestrates warm-up, and automatically triggers a healing protocol when scores drop so cold sends never go out from a burned inbox.
What we build.
Mailbox and domain inventory
Every sending mailbox and domain in one place, with health, age, daily limits, and current sending tool side by side.
Daily deliverability checks
Automated placement tests, blacklist scans, SPF/DKIM/DMARC validation, and inbox-placement scoring across providers.
Warm-up orchestration
PlusVibe and Instantly warm-up are turned on, paced, and rotated automatically based on each mailbox's current health.
Automatic healing
When a mailbox drops, the app pauses sends, triggers a healing protocol (warm-up boost, volume cut, content rotation) and re-enables it only when scores recover.
Sending tool routing
Healthy mailboxes get routed to Smartlead campaigns, recovering ones go to warm-up only. No manual juggling between tools.
Outcomes.
Higher primary-inbox placement, fewer burned domains, and no more guessing which mailboxes are safe to send from. The team stops fighting deliverability and starts shipping campaigns.
Built on your stack.
- ✓Instantly
- ✓PlusVibe
- ✓Zapmail
- ✓Smartlead
- ✓Make
- ✓n8n
- ✓No lock-in. Your team owns it.
FAQ
Deliverability, answered straight.
Why a separate mailbox manager?
Smartlead, Instantly, and Lemlist each manage their own mailboxes in isolation. When you scale past a handful of domains, no single tool gives you a true cross-stack view of deliverability or automatic healing.
What is mailbox healing?
A protocol that runs when a mailbox's inbox-placement score drops: pause cold sends, dial up warm-up, rotate content, give it days to recover, then return to production only when scores are back.
Will this fix a domain that's already burned?
Sometimes. Heavily blacklisted domains are usually faster to retire than to heal. The manager makes that call explicit so you stop dragging dead domains into campaigns.
Does this replace Instantly or Smartlead?
No. It sits above them and tells them what to do. You keep your sending tools.
How many mailboxes does this scale to?
We've run it across hundreds of mailboxes for agency-style setups. The design is the same whether you have 10 or 500.