Which email API is the cheapest?

It depends on your volume. At 50,000 emails a month, SendGrid Essentials ($19.95), Mailumi Pro and Resend Pro ($20) cost about the same. At 250,000 emails, Mailumi Scale costs $80 and the other providers compared here cost between $166.95 and $249. Below 10,000 emails a month, Brevo Starter ($9 for 5,000) and Mailgun Basic and Postmark Basic ($15 for 10,000) are the lowest-priced paid plans.

Which email API has the biggest free plan?

Brevo includes the most free emails: 300 a day for campaigns and transactional email together. Resend includes 3,000 a month (up to 100 a day) and Mailumi 1,500 a month (up to 50 a day). Mailgun allows 100 a day and Postmark 100 a month, while SendGrid offers a 60-day trial and Mailchimp Transactional up to 500 trial emails.

Which email APIs keep data in the EU?

Mailumi and Brevo store data in the EU on every plan. Mailgun can keep messages and logs in its EU region per domain but replicates account data globally, and SendGrid offers EU data residency on its Pro and Premier plans. Resend, Postmark and Mailchimp store data in the United States.

Can I switch email API later?

Yes. Most providers take the same basics: a sender, recipients, a subject and an HTML or text body. Verify your domain with the new provider while the old one keeps sending, move traffic step by step and remove the old DNS records at the end. The migration guide maps the fields of Resend, SendGrid, Mailgun and Postmark.

Email API Comparison 2026: Prices and Features

How to choose an email API.

Start with your monthly volume and how fast it will grow. Plans that cost the same at 50,000 emails can differ by more than double at 250,000, because some providers include more emails per dollar on larger plans while others charge for every extra block.

Then list what you need besides sending: receiving email in your app, SMTP for software that cannot call an API, campaigns for announcements, and where your data is stored if you work under GDPR.

Email APIs built for developers.

Resend, Postmark, Mailgun and SendGrid focus on email sent from code. Resend has a generous free plan and SDKs for many languages, Postmark is known for transactional email, Mailgun offers inbound routing and many add-ons, and SendGrid suits large senders that need dedicated IPs and subusers.

Marketing platforms with an API.

Mailchimp and Brevo started as marketing platforms and also sell transactional email. Mailchimp Transactional needs a Standard or Premium marketing plan and is priced in blocks of 25,000 emails. Brevo plans share one monthly volume between campaigns and transactional email, and Brevo keeps its data in the EU.

Where Mailumi fits.

Mailumi is built for product teams that want sending, receiving and campaigns in one plan: 1,500 free emails a month, 50,000 for $20 and 250,000 for $80. Email data is stored in the EU on every plan, inbound email arrives as signed webhooks and SMTP is included on Pro and Scale. The largest platforms offer extras that Mailumi does not, such as dedicated IPs and marketing automation.

Email APIs compared

Provider	Free option	50,000 emails/month	250,000 emails/month	Inbound email	Where data is stored
Mailumi	1,500/month (50/day)	$20	$80	Every plan	EU, on every plan
Resend	3,000/month (100/day)	$20	$170	Included	United States
SendGrid	60-day trial, 100/day	$19.95	$166.95	Inbound Parse webhook	EU only on Pro and Premier
Mailgun	100/day	$35	$215	1 route on Free, full routing from Foundation	US or EU per domain; account data global
Postmark	100/month	$55	$245	Pro and Platform	United States
Mailchimp Transactional	Up to 500 trial emails	$60	$220	Inbound routes	United States
Brevo	300/day	$56	$249	Inbound parsing	EU

Prices from each provider’s public pricing page: Resend, SendGrid, Mailgun and Postmark checked 7 October 2026, Mailchimp and Brevo checked 18 October 2026. Monthly prices in USD, excluding taxes, for the cheapest published plan that includes that many emails. Mailchimp Transactional includes the smallest Standard plan it requires. Postmark has no 250,000 tier, so its price is for its Basic plan with 300,000 emails. Where data is stored comes from each provider’s documentation, checked 6 October 2026 and 18 October 2026.

Email API comparison: common questions

Sources

Sources checked 6, 7 and 18 October 2026. Third-party features and prices may change.

Email API comparison: seven providers side by side.