Running multiple client domains through one email API account

Agencies and freelancers managing transactional email for several clients hit a specific problem most single-tenant pricing pages don't address: one account, many domains, and a real need to know which client's sending is actually driving the bill.

What matters more than the tier price

Envello's Scale tier supports up to 100 verified domains on one account, with usage-by-domain reporting that breaks down sending volume per domain rather than showing one undifferentiated account total. For an agency, that reporting is arguably more valuable than the raw per-email rate, since it's what lets you actually bill clients accurately or spot which client's integration is misbehaving without guessing.

The practical setup

Verify each client's sending domain separately under the same account, keep API keys scoped where it makes sense (team roles, covered in a separate post, help here if more than one person touches the account), and use the usage-by-domain view as your actual source of truth for client-level billing rather than trying to reconstruct it from raw logs.

The honest limit

This is one account with domain-level visibility, not a multi-tenant platform with separate billing per client baked in. If you need to hand a client their own fully separate account and billing relationship, that's a different setup (a separate signup per client) rather than something usage-by-domain reporting solves on its own.