Most email tools charge by subscriber count. 5,000 subscribers costs X per month whether you send 1 email or 50. That pricing model penalizes you for having a large list, even if you don't email them often.

Pay-per-email pricing flips this. You pay for what you send, not who you store. Send 1,000 emails, pay for 1,000. Send 100,000, pay for 100,000. Your subscriber list can be 50,000 and if you only send one campaign a month, you pay for 50,000 sends, not 50,000 contacts.

This model works best for: transactional email (unpredictable volume), infrequent senders (monthly newsletters to large lists), and businesses with many contacts but low email frequency.

The 7 Best Options

1. Sequenzy

Best for: SaaS companies wanting affordable per-email pricing with full marketing automation

Sequenzy offers usage-based pricing that scales with your sending volume. The platform charges a low base rate plus per-email costs, making it cost-effective for SaaS companies with variable sending patterns. At 10,000 emails/month, you're paying significantly less than subscriber-based platforms that charge for your entire list.

Unlike pure infrastructure tools like SES, Sequenzy includes full marketing automation, a drag-and-drop editor, behavioral triggers, and native Stripe integration. You get pay-per-email economics without sacrificing features. The platform handles both transactional and marketing email, so you're not paying for two separate services.

Pricing: From $29/month including 10,000 emails, additional sends at competitive per-email rates What's included: Full marketing platform, automation, drag-and-drop editor, Stripe integration, analytics What's not included: Dedicated IP (available on higher plans) Best for: SaaS companies wanting marketing features with usage-based economics

2. Amazon SES

Best for: The cheapest pay-per-email option at any volume

Amazon SES charges $0.10 per 1,000 emails. That's it. No subscriber fees, no monthly minimums, no tier complexity. At 100,000 emails/month, you're paying $10. At 1 million, $100.

The trade-off is that SES is pure infrastructure. No drag-and-drop editor, no automation builder, no campaign management UI. You're sending via API or SMTP. You build everything else yourself. But for teams with engineering resources who want the lowest possible email cost, SES is unbeatable.

Pricing: $0.10 per 1,000 emails (+ data transfer costs) What's included: Sending API, SMTP, deliverability tools, event notifications What's not included: UI, templates, automation, analytics dashboard, campaign management Best for: Technical teams, high-volume transactional email, cost-sensitive operations

3. Postmark

Best for: Pay-per-email with the best transactional deliverability

Postmark charges per email sent with plans starting at $15/month for 10,000 emails. The per-email cost decreases at higher volumes. At 300,000 emails/month, the per-email cost drops to about $0.08 per 1,000.

Unlike SES, Postmark includes a full dashboard, template management, bounce handling, and analytics. The deliverability is consistently among the best in the industry, especially for transactional email. You get the pay-per-email model without sacrificing features or support.

Pricing: From $15/month for 10,000 emails, scaling with volume What's included: Dashboard, templates, analytics, bounce management, inbound email What's not included: Marketing automation, campaign builder (marketing emails available as add-on) Best for: Transactional email priority, SaaS products, applications needing reliable delivery

4. Mailgun

Best for: Developer infrastructure with flexible pay-per-email pricing

Mailgun offers a pay-as-you-go plan alongside its subscription tiers. The Flex plan charges $1.00 per 1,000 emails with no monthly minimum, and includes the full API, email validation, and basic analytics.

At higher volumes, the Foundation plan ($35/month for 50,000 emails) brings the per-email cost down. Mailgun also offers email validation (verify addresses before sending), inbound email processing, and IP management, making it a complete email infrastructure.

Pricing: $1.00 per 1,000 emails (Flex), $35/month for 50,000 (Foundation) What's included: Sending API, SMTP, email validation, inbound processing, logs What's not included: Marketing features, drag-and-drop editor, automation Best for: Developers, variable volume sending, applications needing email validation

5. SendGrid

Best for: Pay-per-email that scales from free to enterprise

SendGrid's free tier includes 100 emails/day. The Essentials plan starts at $20/month for 50,000 emails/month, making the per-email cost about $0.40 per 1,000. At higher tiers, costs decrease further.

SendGrid includes both transactional and marketing email capabilities. The Marketing Campaigns feature (with templates, campaigns, and basic automation) is included in paid plans. For teams that want one platform for both transactional and marketing with usage-based pricing, SendGrid covers both.

Pricing: Free for 100/day, from $20/month for 50,000 emails What's included: Transactional API, marketing campaigns, templates, analytics What's not included: Advanced automation, CRM features Best for: Teams needing transactional + basic marketing, scaling from free

6. Resend

Best for: Developer-friendly pay-per-email with the best DX

Resend's pricing is based on email volume. The free tier includes 3,000 emails/month. The Pro plan at $20/month includes 50,000 emails with additional emails at $0.40 per 1,000.

Resend's value is the developer experience, not just the pricing model. React Email support, TypeScript SDK, clean API, and excellent documentation. You pay per email sent and get the best development experience in the category.

Pricing: Free for 3,000/month, $20/month for 50,000, $0.40 per 1,000 additional What's included: Full API, React Email, webhooks, domains, audiences What's not included: Marketing automation, visual campaigns, sequences Best for: Developers building transactional email, React/Next.js applications

7. SparkPost (MessageBird)

Best for: High-volume pay-per-email with predictive deliverability

SparkPost charges per email with volume-based pricing that gets very competitive at scale. For businesses sending millions of emails per month, SparkPost's per-email costs can be lower than SES. The platform includes predictive deliverability tools that optimize inbox placement.

The enterprise features (dedicated IPs, subaccount management, detailed analytics) make SparkPost suitable for large-scale operations. The API is comprehensive, and the platform handles both transactional and marketing email at volume.

Pricing: Usage-based, competitive at high volume What's included: API, SMTP, deliverability tools, analytics, subaccounts What's not included: Marketing UI, campaign builder (API-only for marketing) Best for: High-volume senders (1M+ emails/month), enterprises, ESP-level operations

Pay-Per-Email vs. Per-Subscriber Pricing

When Pay-Per-Email is Cheaper

Large list, low frequency: 50,000 subscribers emailed once a month = 50,000 emails. At pay-per-email rates, this costs $5-50 depending on the platform. Per-subscriber pricing might be $200+/month.
Variable volume: Some months you send 10,000 emails, others 100,000. Pay-per-email scales with actual usage rather than fixed monthly fees.
Transactional email: Volume is unpredictable and tied to user activity. Pay-per-email aligns cost with actual usage.

When Per-Subscriber is Cheaper

Small list, high frequency: 1,000 subscribers getting weekly emails = 4,000-5,000 emails/month. Per-subscriber plans at this size ($15-30/month) can be cheaper than pay-per-email.
Unlimited sends: Many per-subscriber plans include unlimited email sends. If you email your list frequently (multiple times per week), per-subscriber is usually cheaper.
Marketing features: Pay-per-email platforms tend to be infrastructure-focused. Getting marketing automation, campaign builders, and visual editors usually means per-subscriber pricing.

Cost Comparison at 10,000 Emails/Month

Platform	Model	Monthly Cost
Amazon SES	Pay-per-email	~$1
Postmark	Pay-per-email	$15
Mailgun	Pay-per-email	$10 (Flex)
SendGrid	Pay-per-email	$20 (Essentials)
Resend	Pay-per-email	$20 (Pro)

Cost Comparison at 100,000 Emails/Month

Platform	Model	Monthly Cost
Amazon SES	Pay-per-email	~$10
Postmark	Pay-per-email	~$70
Mailgun	Pay-per-email	$75 (Scale)
SendGrid	Pay-per-email	$50 (Pro)
Resend	Pay-per-email	$20 + overages

FAQ

Is Amazon SES really that cheap? Yes. $0.10 per 1,000 emails is the real price. The catch is you're paying for infrastructure, not a product. You need to build or buy everything else: templates, automation, analytics, bounce handling, and campaign management.

Can I use pay-per-email for marketing campaigns? Yes, but most pay-per-email platforms are designed for transactional email. SendGrid is the exception, offering both transactional and marketing features with pay-per-email pricing. For full marketing automation, you'll typically need a per-subscriber platform.

What about email overages? Most pay-per-email platforms handle overages gracefully. Send more than your plan includes and you're charged a per-email overage rate. Unlike per-subscriber plans that might block your sending, pay-per-email just adjusts the bill.

Should I use pay-per-email for a SaaS product? For transactional email (password resets, notifications, receipts), yes. Pay-per-email aligns cost with usage. For marketing email (campaigns, sequences, lifecycle), a per-subscriber platform with automation features is usually a better fit.