The Real Cost of Email APIs: Pricing Comparison 2026
Email pricing is deliberately confusing
Every email API has a pricing page. None of them make it easy to compare. Resend charges per email with daily limits. SendGrid uses tiered plans with different feature sets at each level. Postmark charges per email with no free tier. Mailgun has hidden overage fees. AWS SES is cheap per-email but expensive in engineering time. The result: developers pick a provider based on the marketing page, then get surprised by the real cost 3 months later. This guide cuts through the marketing and compares what you'll actually pay.
Free tier comparison: what you actually get
AISend: 3,000 emails/month (100/day), one verified sending domain included, no credit card required. Resend: 3,000 emails/month (100/day limit), single provider, credit card not required. SendGrid: 100 emails/day (3,000/month), limited analytics, no dedicated IP. Postmark: no free tier (starts at $15/month for 10,000 emails). Mailgun: no free tier (starts at $35/month). AWS SES: 3,000 emails/month free (if sending from EC2), but requires significant setup time. The key difference at the free level: AISend and Resend are essentially identical — same 3,000/month, same 100/day cap, one custom domain each. Pick on price at the paid tier, or on whether you want native MCP support for AI agents. SendGrid's daily limit of 100 is restrictive for testing. Postmark and Mailgun have no free option at all.
At 50,000 emails/month: where costs diverge
This is the sweet spot where most growing SaaS apps land. AISend Pro: $14/month (50,000 emails, 10 domains, built-in MCP server). Resend Pro: $20/month (same volume, larger track record, React Email). SendGrid Essentials: $19.95/month (limited features, complex API). Postmark: $50/month (excellent deliverability reputation). Mailgun Foundation: $35/month (basic features). AWS SES: $5/month (raw sending only — add $2,000-5,000/month in engineering time for bounce handling, analytics, and monitoring that other providers include). At this volume, AISend is the cheapest full-featured option. SES looks cheapest on paper but the engineering overhead makes it the most expensive in practice.
Hidden costs most pricing pages don't show
Overage fees: SendGrid charges steep per-email overages when you exceed your plan limit — a surprise $200 bill is common. Feature gating: SendGrid reserves advanced deliverability features for Pro plans ($89.95/month). Resend charges $20/month for the same 50,000 emails. Dedicated IPs: most providers charge $20-50/month extra for a dedicated IP, which some very-high-volume senders opt for (though a well-authenticated, warmed shared setup handles most workloads). Support: enterprise-level support typically adds 20-30% to your bill. Migration cost: switching providers takes 2-20 hours of engineering time depending on how deeply integrated your email is. AISend's Resend-compatible API keeps that migration cost near zero in both directions — which is the point: we'd rather you be able to leave cheaply than be locked in.
Our honest recommendation
Under 3,000 emails/month: use AISend or Resend free tier — both are solid. At 10K-50K: AISend Pro ($14) is the cheapest of the modern APIs; Resend ($20) buys you a longer track record for the difference. At 50K-100K: AISend Business ($63) versus SendGrid Pro ($89.95). At 100K+: AISend Scale ($149 for 500K) or negotiate enterprise pricing. Only use raw SES if you have a dedicated email engineering team to build and maintain the infrastructure. The cheapest email is not the one with the lowest per-email price — it's the one that actually reaches the inbox. A 95% delivery rate at $0.001/email costs more in lost users than a 99% delivery rate at $0.003/email.
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