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Transactional Email · decision tool

Which email API should I use?

Set your monthly volume and constraints — get a ranked email-provider verdict with the real monthly bill. Resend, Postmark, SES, Mailgun, SendGrid.

Prices verified 2026-07-15 against official pricing pages · fit weights are our estimates (see methodology) · share the URL to share your configuration

As of Jul 2026, with 20,000 emails/month, a $30 budget for this slot, Resend ranks first for these inputs at 83% fit and a StackSays-estimated $20.00/month (SendGrid: 83% fit, $19.95/month). Fit weights are our estimates; prices trace to official pages. Change any input below and the verdict recomputes.

Your situation

The verdict updates as you move these.

Toss-up — your priorities decide, not the tools

Resendfit 83% · est $20.00/mo

Developer-first email API with React Email templates and a generous free tier

vs SendGrid: fit 83% against 83%, est $20.00 against $19.95 per month — genuinely close; read both risk lists below

Resendfit 83%
$20.00/mo
SendGridfit 83%
$19.95/mo
Amazon SESfit 81%
$2.00/mo
Postmarkfit 80%
$29.50/mo
Mailgunfit 69%
$33.00/mo

The decision, in plain words

For a solo builder at 20,000 emails/month and a $30.00/mo budget for the email provider slot, Resend leads at 83% fit and $20.00/mo. The two rules doing the work: budget fit (~$20/mo is 67% of your $30/mo budget); batteries included (Bundles marketing email, template tooling, inbound parsing — fewer services to glue at team size 1).

SendGrid is a genuine coin-flip here (83% fit, $19.95/mo, $0.05 cheaper) — read both risk lists and pick the failure mode you prefer.

Honest weak spot of the pick: growing — our estimate from ecosystem age, docs and hiring pool.

Generated from the calculation above — every number traces to the sourced data; nothing here is written by an AI making things up.

Why Resend scores 83%

Budget fit (weight 30, our estimate) — ~$20/mo is 67% of your $30/mo budget+25
Batteries included (weight 12, our estimate) — Bundles marketing email, template tooling, inbound parsing — fewer services to glue at team size 1+12
Exit cost (weight 4, our estimate) — Standard SMTP + API — switching providers is a config change plus warmup+3.2
Ecosystem maturity (weight 8, our estimate) — growing — our estimate from ecosystem age, docs and hiring pool-1.6
Free-tier runway (weight 10, our estimate) — Free tier exists (3,000 emails/month (100/day), 1 domain) — a cheap staging/dev lane even after you outgrow it+4
Total (lines sum exactly)42.6
Possible range −64…+64 (sum of active rule weights) · fit % = (total + max) / (2 × max)(42.6 + 64) / 128 = 83%

How the $20.00/mo estimate is calculated

Pro 50K base — includes 50K emails$20.00
Monthly total (lines sum exactly)$20.00

What could change this verdict

Cost risk

Estimated now (StackSays estimate, not your final bill)$20.00/mo · Pro 50K
Free-tier statusFree tier exceeded (emails 20K > 3K cap)
Next known billing thresholdat 50K emails, overage starts ($0.9/K)

Official prices verified 2026-07-15; calculation is deterministic code over those prices.

At a glance

ToolFree tierPaid entryVerified
Resend3,000 emails/month (100/day), 1 domainPro 50K $20/mo2026-07-15
Postmark100 emails/month, full featuresBasic $15/mo2026-07-15
Amazon SESNo free tierPay-as-you-go — Flat $0.10/1K sent. Free tier is 3K/month for the first 12 months only — not permanent. Dedicated IP $24.95/mo optional2026-07-15
Mailgun100 emails/dayBasic $15/mo2026-07-15
SendGridNo free tierEssentials $19.95/mo2026-07-15
Where did you land?anonymous, one click

Data sources

ToolSourceVerified
ResendResend pricing page2026-07-15
PostmarkPostmark pricing page2026-07-15
Amazon SESAmazon SES pricing page2026-07-15
MailgunMailgun pricing page2026-07-15
SendGridThird-party 2026 pricing tracker (official page redirect-loops)2026-07-15

A monitor re-checks these pages for changes; when a vendor moves a price, the date updates and every verdict recomputes.

People also ask

Is Resend free forever?

The free tier is permanent: 3,000 emails/month capped at 100/day, one domain (verified 2026-07-15). It's a real production lane for small apps — the cap you'll hit first is the 100/day on bursty signup days.

Is SendGrid free forever?

No — SendGrid discontinued its permanent free tier in 2025. New accounts get a 60-day trial (100 emails/day), then must move to Essentials at $19.95/month. If you want a permanent free lane, Resend (3K/mo) and Mailgun (100/day) still have one.

Is Amazon SES free?

Not permanently — the 3K/month free allowance lasts only your first 12 months on AWS (verified 2026-07-15). After that it's $0.10 per 1,000 emails, which is still the price floor of the industry: 100K emails ≈ $10 vs $35–90 elsewhere.

Is Postmark free?

Only a developer tier: 100 emails/month with full features (verified 2026-07-15) — enough to evaluate deliverability, not to run production. Paid starts at $15/month for 10K emails.

Keep deciding