Peeker's pitch is "self-healing inboxes" — burn detection and automatic swaps so dying mailboxes get replaced before they hurt campaigns. CLAYINBOX solves the same problem with free monitoring plus free unlimited replacements. Same destination, different routes.
| Feature | CLAYINBOX | Peeker |
|---|---|---|
| Pricing | Flat $2.50, published | Tiered by inbox count; rates not fully published |
| Providers | GW, M365, Azure, SMTP | Google + Microsoft Azure inboxes |
| Burn detection | Alerts via monitoring suite | ✓ automatic, core feature |
| Automatic inbox swaps | Manual or API-triggered; replacements free | ✓ automatic (flagship feature) |
| Auto-reconnects to sequencer | Via OAuth exports | ✓ silent auto-reconnects |
| Blacklist / DNS monitoring | ✓ | Deliverability analytics (placement-focused) |
| Placement tests | ✓ unlimited free | ✓ analytics included |
| Replacements cost | Free, unlimited | Swaps included; premium domain swaps extra |
| Unified inbox | ✓ | ✗ |
| Pre-warmed | ✓ | ✗ |
| Send-volume guidance | Flexible | Plan-capped sends/day (~3,735/day Starter) |
| Integrations | One-click + SMTP universal | Instantly, Smartlead, EmailBison, Plusvibe via API |
| API | ✓ + MCP | ✓ |
| Whitelabel | ✓ | ✗ |
| Domain isolation | ✓ per-domain workspace | High-density (75/domain) — opposite philosophy |
Peeker's 75-inboxes-per-domain density model concentrates reputation risk per domain vs. our isolation-first model.
The self-healing loop is real engineering — burn detection from actual sending signals, automatic swaps before campaigns degrade, silent reconnects, Slack alerts. For teams running 250+ inboxes who never want to think about infrastructure health, the automation depth is the best in this niche.
Breadth and transparency. Peeker covers Google and Azure; CLAYINBOX adds M365 and dedicated SMTP, plus pre-warmed accounts, a unified inbox, and whitelabel. Pricing is published rather than tiered-on-request. And the isolation philosophy differs: Peeker stacks up to 75 inboxes on a domain (efficient, but a flagged domain takes down 75 senders); CLAYINBOX isolates each domain in its own workspace so blast radius stays small — with the replacement free when something does burn.
Export inbox inventory, re-provision on CLAYINBOX with more domains at lower density, point your sequencer at the new accounts. Keep Peeker's density math in mind: 75 inboxes/domain converts to ~8–10 domains on our isolation model for the same fleet.
Flat $2.50/mailbox. Warmup, monitoring, replacements, unified inbox — all included.