The email API costs that don't show up on the pricing page

The advertised per-tier price is rarely the whole story for any usage-based API. The costs that actually surprise teams are the ones that only show up once you're past the included volume or need a feature that's gated behind an add-on. Using Envello's own published numbers as a concrete example of what to check, whichever provider you're evaluating:

Overage rates

Envello's Pro tier includes 50,000 to 100,000 emails per month depending on the plan variant, with overages billed at €0.80 per 1,000 emails beyond that. That rate is published on the pricing page, not something you discover on your first invoice after a traffic spike. Check whether a provider you're evaluating publishes its overage rate at all; many don't show it until you're already a customer.

Add-ons that aren't in the base tier price

Dedicated IPs are a real add-on on Envello's Scale tier (€25/month), not bundled into the base price. That's a reasonable and disclosed cost, the kind worth checking for on any provider: does the tier price include everything you'll actually need, or does reaching feature parity require stacking add-ons that change the effective price?

Questions worth asking before you commit

• What's the exact overage rate, and is it published or only visible after signup?
• Which features require an add-on rather than being included in the base tier?
• Does the retention window scale with the tier, or is long retention itself an upsell?
• What happens on a missed payment, immediate suspension or a grace period?