Plans. Free / Essentials / Pro / Enterprise. Pricing page at /pricing. You can change tiers at any time from Settings → Billing.
Overage. Set a hard cap or pay-as-you-go in Settings → Billing. Pay-as-you-go bills at your plan's per-email rate; no markup.
Invoices. Generated on the first of every month for the previous month. Downloadable from Settings → Billing → Invoices. Tax invoices issued for the regions we are registered in.
Annual billing. 17% off any plan when billed annually. Contact sales for multi-year terms.
Cancellation. Cancel anytime from Settings → Billing → Cancel. You retain access through the end of the paid period.