Methodology

Email limits and incomplete totals

Monthly email volume and peak daily sends are separate assumptions. A daily allowance is checked against the peak day, never multiplied by 30 to guarantee eligibility. A known hard cap makes an over-limit workload ineligible; missing peak usage or an unpublished applicable rate makes the total unknown.

Unknown totals remain unknown even when a component is $0. Postal has a free software license, but its hosting and operation costs are additional. A stack containing an unpriced item shows a known subtotal and the missing cost count, not a complete monthly bill.

Volume tiers are separate selectable plans. Scenario recommendations compare eligible computed totals, including overage, and enforce any stated inbound requirement. Per-unit overage is rounded up to a complete published billing unit in this model; confirm vendor invoice rounding for partial units. List-price calculations are not measurements of sending speed, reliability or deliverability. See the sourced email scenarios.

DevToolbox estimates stack cost from first-party vendor pricing pages. It does not invent missing prices, treat unknown as free, or auto-assemble a stack.

Snapshot 2026-09-21.1, hash deca75074777. 137 products, 341 plans, 11 categories. Catalog built 2026-09-21; checked dates appear beside each source.

Computed: every input needed for that plan is numeric and sourced.
Range: a vendor publishes a starting overage rate, so the total can be higher.
Unknown: a required rate, included quantity, or usage value is missing.
Ineligible: the usage is invalid or exceeds a sourced hard limit.