Warmup included free. Isolated, not pooled.
Every mailbox gets warmup automatically — not as a $3/mo add-on, not as a tier upsell. Free, isolated, and matched to a human ramp schedule.
What warmup actually does
Builds sender reputation by sending small volumes to a network of real inboxes that open, reply, and mark as important. Receiving providers (Gmail, Outlook) learn that your mailbox sends mail people want.
The shared-pool problem
Giant warmup pools with tens of thousands of senders are recognizable patterns — providers can identify pool participants by behavior. Reported open-rate drops on big-network warmups are not coincidence. We use a smaller isolated network instead.
Ramp schedule (default)
Week 1: 5–8/day. Week 2: 10–15/day. Week 3: full speed (15+/day). Customizable per mailbox, automatically paused on flags.
InboxKit warmup $3/mo add-on · Zapmail paid add-on · CLAYINBOX $0
Common questions
More from the platform
Real Workspace accounts with full admin access, automated DNS, isolated one-domain workspaces, and free warmup — at less than a third of Google's retail price.
Skip the 14–21 day ramp. Accounts arrive with established reputation — +$2/mo over standard, vs $5 at Icemail and ~$10 at Instantly DFY.
Three layers of monitoring on every mailbox — continuous blacklist scans across 50+ RBLs, DNS drift detection, unlimited placement tests. Free, not gated.