§04 · Email · Which email API?

Transactional email APIs

Transactional email is the mail your app sends one person at a time: sign-up confirmations, password resets, receipts. What matters is deliverability, a clean API and predictable pricing as volume grows, and prices at 50,000 emails a month range from free to over $50.

30 tools 19 with a free option Checked 28 Sept 2026 Cost calculator →
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Where we would start, by stage

Editorial picks from the data below, never paid. They change when prices or free tiers do; the full table is underneath.

Hobby $0–10/mo
Resend

3,000 emails a month free (100 a day), a clean API and inbound on every plan.

From $20/mo for 50,000 emails

Indie up to ~$50/mo
Postmark

A transactional-only service from $15/mo for 10,000 emails, with inbound on Pro and Platform.

From $15/mo for 10,000 emails

Startup up to ~$500/mo
Twilio SendGrid Email API

$19.95/mo covers 50,000 emails; a dedicated IP is included from the Pro plan.

From $19.95/mo for 50,000 emails

Scale-up usage-driven
Amazon SES

About $5 for 50,000 emails at à la carte rates, with dedicated IPs from $24.95/mo.

From $0.10 per 1,000 emails

Enterprise contracts
Mailgun

Plans from free to enterprise, an EU region and inbound routing.

From $15/mo for 10,000 emails

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All 30 compared

A to Z · never paid placement

30 tools

Tool From Free option Free50k emails/moDedicated IPInbound Stages
AhaSend ahasend.com · EU
$10/mo Free tier 1,000/month About $22.50 (Pro $10 + 25k at $0.50/1k) Access at 100k on Pro; included at 300k+ on Max Yes (inbound routing)
Amazon SES aws.amazon.com · EU
Usage-based No None; new AWS accounts get up to $200 credits $5 (a la carte, plus attachment data) $24.95/mo per IP, or managed from $15/mo Yes, $0.10/1,000 plus chunks; Mail Manager
Azure Communication Services Email learn.microsoft.com · EU
Usage-based No None About $12.50 plus data transfer — Not offered in the docs we read
Bento bentonow.com
$29/mo No — — — —
Brevo brevo.com · EU
$9/mo Free tier — — — —
Cloudflare Email Service developers.cloudflare.com
$5/mo No 3,000/month on Workers Paid ($5) About $21.45 (incl. $5 Workers Paid) — Yes, Email Routing, unlimited on all plans
Elastic Email API elasticemail.com
$19/mo Free tier 3,000/month (100/day) $19/mo (Starter) or $49/mo (Pro) Private IP add-on $40/mo Not listed on the pricing page
Emailit emailit.com · EU
Usage-based No None (free tier retired) About $10 in credits at $0.20/1k $300/year add-on Yes
Lettermint lettermint.co · EU
€10/mo Free tier 300/month €40/mo (Starter 50,000) €50/mo add-on, Pro plan, 300k+ emails Yes, from Starter
Loops loops.so
$49/mo Free tier — — — —
$20/mo No Up to 500 demo sends to your verified domain $40/mo in blocks + Mailchimp plan $29.95/mo add-on Yes (inbound email handling)
Mailcoach mailcoach.app
$9.99/mo Trial — — — —
Maileroo maileroo.com
$10/mo Free tier 3,000/month (+1,000 inbound) Not readable (slider) Free on 250k+ plans; extra $50/mo each Yes, all plans
MailerSend mailersend.com
$7/mo Free tier 500/month $35/mo (Starter) Enterprise only, over 100K emails/week Yes (inbound routing)
Mailgun mailgun.com · EU
$15/mo Free tier 100/day $35/mo (Foundation) Access at 50k, 1 included at 100k+; extra $59/mo Yes (1 route free, 5 Basic, full Foundation+)
Mailjet mailjet.com · EU
$9/mo Free tier 6,000/month (200/day) Not readable (slider) 1 IP on Premium 100k+ plans Not listed on the pricing page
MailPace mailpace.com · EU
$4/mo No 100/month plan on request Not readable (slider) — Yes, all plans
$15/mo Free tier 4,000/month (150/day) $20/mo (Basic 50K) Included on Business ($85+) Yes, all plans
Notifuse notifuse.com · OSS · EU
$19/mo Open source — — — —
Plunk useplunk.com · OSS · EU
Usage-based Free tier 1,000/month About $50 ($0.001/email) — Yes (webhook notifications)
Postmark postmarkapp.com
$15/mo Free tier 100/month Not shown without the slider; $15 plan + $1.80/1k over 10k $50/mo per IP, 300k+ emails/mo, Pro or higher Yes, Pro and Platform
Resend resend.com
$20/mo Free tier 3,000/month (100/day) $20/mo (Pro) $30/mo add-on on Scale, 3,000+ emails/day Yes, all plans
Usage-based Free tier 300/month About €12.43 (Essential, pay as you go) Managed dedicated IP on Scale (€80/mo) Not offered on the pages we read
SMTP2GO smtp2go.com
$10/mo Free tier 1,000/month Not readable (slider) Included on Professional ($75+) Not listed on the pricing page
SocketLabs socketlabs.com
$39.95/mo Trial First month of Core free (trial) Core $39.95 + $0.0013 per email over 40k Included on Pro ($89.95) Not listed on the pricing page
SparkPost sparkpost.com
$15/mo Free tier 1,000/month $15/mo (Startup 50K) $24.95/mo each, Growth and above, up to 5 Not listed on the pricing page
Sweego sweego.io · EU
€10/mo Free tier 100/day Individual 50K tier; price not readable Available on Startup, included on Scaleup Yes, paid plans
$19.95/mo Trial 60-day trial, 100/day $19.95/mo (Essentials 50k) 1 included on Pro ($89.95+) Yes (Inbound Parse webhook)
useSend usesend.com · OSS
$10/mo Free tier 3,000/month (100/day) on cloud $20 on cloud (transactional) — Listed as not yet done in the README
Zoho ZeptoMail zoho.com · EU
Usage-based No First credit (10,000) free, expires in 1 month About $12.50 in credits Annual add-on, some data centers only Not offered on the pages we read

Prices are list prices as published by each vendor, in their currency, excluding tax. "From" is the cheapest paid plan; sorting converts currencies approximately. Open a tool for its plans, sources and the date checked.

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How to choose an email API

  • Estimate your monthly volume and compare the price at that volume, not the entry price. The email cost calculator does this for you.
  • Keep transactional and marketing mail on separate streams or providers, so a newsletter complaint cannot hurt password resets.
  • Check the free tier: some are a daily cap, some a monthly cap, some expire after a trial period.
  • If you need to receive mail (replies, parsing), check inbound support.
  • A dedicated IP only helps at steady high volume; below that, a shared pool with a good reputation usually delivers better.

Questions

What is the cheapest transactional email service?

At high volume Amazon SES is usually cheapest per email, but it needs more setup. The table and the email cost calculator show each provider's price at 10,000 to 500,000 emails a month.

Can I send transactional email from my own SMTP server?

You can, but new servers and IP addresses start with no reputation, and major mailbox providers now require SPF, DKIM and DMARC. A transactional provider handles reputation, bounces and complaints for you.

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Comparisons and pricing changes

Recent changes

  • New Amazon SES accounts default to the Essentials plan

    Amazon SES · source ↗

  • ZeptoMail pricing update for new sign-ups

    Zoho ZeptoMail · source ↗

  • Postmark Pro and Platform features available at 10,000 emails

    Postmark · source ↗

  • SendGrid retires its Free Email API plan

    Twilio SendGrid Email API · source ↗

  • New SendGrid accounts get a 60-day trial instead of a free plan

    Twilio SendGrid Email API · source ↗

All pricing changes →