Pay only for what you send.
3,000 emails every month are free. After that it's a flat $0.40 per 1,000 — no plan tiers, no contact-count fees, and a spend cap so you stay in control.
After your free 3,000 emails each month. Billed per 1,000, rounded up.
Start free →- Transactional send API (single + batch)
- Visual template builder
- Unlimited sending domains
- SPF, DKIM & DMARC alignment
- Automatic bounce & complaint suppression
- Event webhooks
- Message status lookup
- Scoped API keys
- Per-org hard spend cap
- Free
- 3,000
- Billable
- 47,000
- Blocks ×1k
- 47
3,000 emails free each month, then $0.40 per 1,000 (billed per 1,000, rounded up). No subscription.
How billing works
Send freely
Your first 3,000 emails each billing period cost nothing — no card required to start.
Pay per 1,000
Beyond the free tier, overage is $0.40 per 1,000 emails, rounded up to the next thousand.
Cap your spend
Set a monthly spend cap; sending pauses at the cap so you never get a surprise bill.
Pricing FAQ
How does MailStack pricing work?
MailStack is usage-only. You get 3,000 emails every month for free. After that, you pay $0.40 per 1,000 emails sent. There is no subscription, no plan tier, and no minimum — you pay only for what you send.
Is there a free tier?
Yes. Every account includes 3,000 emails per month at no cost, and the free allowance resets at the start of each billing period. Many side projects never pay anything.
What counts as a billable email?
Each accepted recipient send counts as one email against your monthly usage. Emails rejected before queueing (for example, sends to suppressed recipients or invalid requests) are not counted.
Can I cap my spend?
Yes. You can set a hard monthly spend cap per organization. Once your projected overage cost reaches the cap, MailStack stops accepting new sends until the next period, so you never get a surprise bill.
Do I need a credit card to start?
No. You can send up to your 3,000-email monthly free allowance without a payment method. A card is only required once you exceed the free tier.
How is overage billed — per email or per thousand?
Overage is billed per 1,000 emails, rounded up. For example, sending 4,200 emails in a month means 3,000 free plus 1,200 billable, which rounds to 2 blocks of 1,000 — $0.80 for the month.
Does my contact list size affect the price?
No. Unlike contact-tier pricing, MailStack never charges based on how many contacts or subscribers you store. You are billed strictly on emails sent.