Research first. Revenue second.

Primary-source preference

EmailCostEngine prioritizes provider-owned pricing pages, official help centers, billing documentation and official program terms. Third-party roundup pages are not treated as authoritative pricing evidence.

Evidence classification

Pricing may be exact, derived from an explicit rule, dynamic or incomplete. Feature evidence is classified as included, limited, add-on, unsupported or unverified. Unverified evidence does not become a positive claim.

Commercial separation

Affiliate payout, commission rate, advertising relationship or partnership status is not an input to cost rank, feature compatibility, savings or break-even calculations.

Updating information

Source verification dates are stored and exposed through the site. Data that exceeds freshness thresholds is visibly identified so users can understand the age of supporting evidence.

Corrections

Material factual errors should be corrected at the data/model layer when possible so the change propagates across calculators, provider pages and comparisons. See the Corrections Policy.

AI-assisted work

Automation or AI may assist research, drafting, testing or maintenance, but it should not convert uncertain third-party information into a verified fact without supporting evidence.