Domain density planning

Plan how many inboxes each sending domain should carry.

Estimate domain count from inbox density and per-domain daily caps so no single domain absorbs more volume than its risk profile supports.

Calculator

Model the send load.

GTM plans around three inboxes per domain and risk-profile daily caps per domain. Density is a planning input; DNS readiness, smoke tests, and launch gates still decide when a domain sends.

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Capacity recommendation

Shared SMTP control plane

Lowest-friction package for readiness-gated SMTP inboxes on managed shared capacity.

Estimated monthly cost

$226

Planning estimate only.

Monthly emails

15,000

5,000 prospects x 3 touches.

Daily send requirement

693

Spread across 5 send days/week.

Recommended inboxes

28

25 emails/inbox/day cap.

Recommended domains

10

3 inboxes/domain by default.

Infrastructure caps

SMTP IP capacity
2
Domain daily cap
100
IP daily cap
3,000
Warmup assumption
30 days

Per-IP utilization should stay below 80 percent before adding traffic. Scale horizontally with more IPs or domains before raising inbox caps.

Cost assumptions

Shared SMTP control plane platform planning baseline$99
28 inboxes$112
10 managed domains$15

Domain registration, taxes, discounts, support tiers, and real Microsoft/Google reseller SKUs can change the final quote.

Readiness notes

  • Treat this as a planning estimate, not a quote or deliverability guarantee.
  • Readiness gates, seed-placement evidence, and fresh SMTP/IMAP smoke tests still decide exportability.
  • GTM-managed shared SMTP capacity; IP count is a planning signal, not a line item.

Common questions

Why plan three inboxes per domain?

Concentrating many inboxes on one domain ties all of their reputation to a single domain and saturates its daily cap quickly. Three per domain keeps per-domain volume low while limiting how many domains you must register and authenticate.

What happens when a domain hits its daily cap?

In this model the extra volume requires another domain rather than pushing existing inboxes harder. Conservative profiles cap a domain at 100 emails per day; higher-risk profiles raise the cap but increase exposure.

Related workflows

Inboxes per domain guide

The reasoning behind inbox density and per-domain caps.

Cold email domain checker

Check DNS authentication and domain age before assigning inboxes.

Package capacity calculator

Translate capacity assumptions into a package-level planning estimate.

Inbox readiness checker

Check whether a domain is set up to support the capacity you just planned.

Next step

Model domains, inboxes, and SMTP capacity as one package estimate.

Plan domain and inbox capacity