Multi-tenant white-label.

• Web agency: each client sees only their own logs, credentials and stats.
• SaaS platform: your software offers email sending to your customers, but you pay a single consolidated bill.
• Holdings / groups: separation between brands while keeping central management.

Each sub-account has: separate API/SMTP keys, its own sending domain, optionally a dedicated IP pool, dashboard access with your logo and domain (e.g. email.youragency.com). No data is shared between sub-accounts.

The master account pays the consolidated total usage. Each sub-account sees its own usage in the dashboard but only the master account receives the invoice. If you want to resell, apply your markup externally — Target SMTP only invoices the operational cost.