Is it really unlimited domains?
Yes. We do not restrict or audit domain connection counts. You can connect as many sending domains as your outbound target strategy requires.
Eliminating seat-based restrictions on email volume
Most cold email relay platforms charge per-mailbox fees, regularly scaling to hundreds of dollars monthly. This forces outreach teams to limit their sending capacity and run excessive volume through single addresses, which damages deliverability health.
Cold Mail Server offers a flat infrastructure rate model. Because we containerize your outbound custom server instances directly, we do not monitor or restrict seat licenses. You can connect as many domains and aliases as required.
This allows you to implement robust domain rotation profiles, ensuring individual mailboxes send a safe volume of emails daily while maintaining large-scale outreach reach.
| Mailboxes | Relays ($2.50/ea) | CMS (Flat) |
|---|---|---|
| 50 mailboxes | $125/mo | $49/mo |
| 200 mailboxes | $500/mo | $49/mo |
| 1,000 mailboxes | $2,500/mo | $49/mo |
Strategy
Why flat-rate pricing changes everything
Pragmatic domain rotation
Outbound best practices require spreading volume. With unlimited domains, you can rotate sending limits safely to maximize deliverability.
Unlimited headroom
Never trim your outreach campaigns to save on monthly software seat licenses. Send to your target list at full capacity.
Multi-client agencies
Support multiple clients with isolated domains. Provision dedicated assets on the fly with no billing surprises.
Technical Specifications
Operational Headroom Configuration
| Feature Capability | Starter Tier | Scale Tier | Agency Tier |
|---|---|---|---|
| Connected Sending Domains | Unlimited | Unlimited | Unlimited |
| Active Mailbox Seats | Unlimited | Unlimited | Unlimited |
| Hourly Send limits | 500 / hr | 1,000 / hr | 2,000 / hr |
| Daily Send limits | 3,000 / day | 10,000 / day | 30,000 / day |
| Outbound API access | No | Yes | Yes |
Billing & Capacity FAQs
Are there any hidden mailbox fees?
No. You pay a flat plan price monthly. Create 10 or 1,000 mailboxes. Your card is never auto-charged for overages.
How do you define plan limits?
Plans are bound by bandwidth capabilities (hourly, daily, and monthly send caps). If you reach your volume limit, sending processes pause until the next cycle restarts.
Can I manage multiple client brands?
Yes. Our dashboard supports domain organization tags, which is ideal for agencies managing outreach for distinct client portfolios.
$0+Annual Savings vs Per-Seat
0%Predictable Flat Rate Billing
0Unexpected Overages or Upgrades
Unlock unlimited domain rotation
Distribute your outbound volume across domains responsibly without worrying about seat-based costs.