# Free email API: 9 permanent plans for developers compared > Compare nine free email API services by monthly volume, daily caps, log retention, domains, and the limit most likely to stop a real application. - **Category:** Provider comparison - **Published:** August 4, 2026 - **Reading time:** 14 min read - **Author:** Maya Chen, Email infrastructure - **Canonical page:** [https://emailbump.com/blog/free-email-api](https://emailbump.com/blog/free-email-api) A free email API can carry a side project, staging environment, or early product for months. The headline allowance is only one constraint. Daily caps, activity retention, domain limits, API request limits, inbound support, and whether the offer expires often decide whether the plan is actually usable. This comparison includes permanent plans rather than short trials. Prices and limits were checked against provider pages on August 4, 2026. We make one of the products in the table—Email Bump—and call out where another provider is the stronger choice. > **Best free email API by use case** > > Choose Mailjet for the largest allowance here, Email Bump for no daily cap plus campaigns, Mailtrap when staging safety matters, Resend for developer experience, Maileroo for inbound email, AhaSend for European infrastructure, or Postmark when long message history matters more than free volume. ## Free email API plans at a glance ### Permanent free plans — checked August 4, 2026 ```text PROVIDER FREE EMAILS DAILY CAP ACTIVITY / LOGS LIMIT TO WATCH Mailjet 6,000 per month 200/day Basic statistics Daily ceiling Email Bump 5,000 per month None* Not tiered by plan US-only region Mailtrap 4,000 per month 150/day 3 days Short history Resend 3,000 per month 100/day 30 days One-domain Free plan Maileroo 3,000 per month None Full analytics Smaller track record AhaSend 1,000 per month None Plan-dependent Transactional only MailerSend 500 per month 100/day 1 day 100 API requests/day Mailgun 100 per day 100/day 1 day History disappears fast Postmark 100 per month None 45 days Testing-sized allowance *Email Bump's shared test domain has an abuse-control limit. Verify your own sending domain for normal production use. Limits and prices change—recheck first. ``` A trial is not a free plan. Twilio SendGrid now gives new API users 100 emails per day for 60 days, then requires a paid plan. Amazon SES no longer gives new customers its former SES-specific 3,000-message allowance; new accounts begin on Essentials, while general AWS credits may temporarily offset the bill. Both are useful evaluations, but neither is a permanent place to keep a small application. ## 1. Mailjet: largest free allowance in this comparison Mailjet includes 6,000 emails per month, an API, SMTP relay, webhooks, and an editor. The practical limit is 200 messages per day. That works well for steady transactional traffic and poorly for a launch, import, or weekly digest that needs most of the monthly allowance at once. Choose Mailjet when maximum free monthly volume matters and the workload can be smoothed across days. If regional processing or company location matters, review its current data-handling terms rather than inferring residency from the company being French. ## 2. Email Bump: best free API when campaigns are part of the product Email Bump includes 5,000 contacts and a shared pool of 5,000 emails per month. Transactional API sends, SMTP, campaigns, segments, flows, webhooks, and inbound email use one account. There is no plan-level daily cap after you verify a sending domain, so an occasional launch can use the monthly allowance when it is needed. The tradeoffs are maturity and geography. Sending is from the United States through Amazon SES, with no EU region, and there are fewer language SDKs than long-running providers. Choose it when replacing separate transactional and marketing subscriptions is the goal. ## One API, campaigns included Start with individual product messages, then use the same contacts, consent state, events, and templates for lifecycle flows and campaigns. - 5,000 combined emails per month - No plan-level daily cap on verified domains - Transactional, marketing, automation, and inbound together [Learn more](https://emailbump.com/docs/transactional-api) ## 3. Mailtrap: best free testing environment Mailtrap’s production sending plan includes 4,000 emails per month at up to 150 per day, one domain, and three days of activity history. Its real advantage is the separate testing sandbox: staging messages are captured before they can accidentally reach customers. A sensible architecture can keep Mailtrap for development and use another provider in production. Transport configuration should already be environment-specific, and preventing a staging password-reset message from reaching a real person is more valuable than keeping every environment on one bill. ## 4. Resend: best free developer experience Resend includes 3,000 transactional emails per month with a 100-per-day cap. Its API, official SDKs, test domain, React Email ecosystem, webhooks, command-line tooling, inbound support, and 24-hour idempotency-key window make it the easiest option here for many application teams. The daily cap is the important constraint: 3,000 monthly messages cannot be used in a single launch. Marketing email is priced separately by contacts, so include that second product in the comparison if newsletters or lifecycle campaigns are on the roadmap. ## 5. Maileroo: best free allowance with inbound email Maileroo pairs 3,000 outbound messages with an inbound allowance, multiple domains, and detailed analytics. That makes it unusually complete for an application that needs replies, support messages, or automated mailbox workflows rather than outbound delivery alone. It is a smaller provider with a shorter public operating record than Mailgun, SendGrid, or Postmark. Evaluate support response, regional handling, export paths, and production references with the same care you would apply to any younger infrastructure vendor. ## 6. AhaSend: best free European transactional option AhaSend includes 1,000 messages per month, unlimited sending domains, and no card requirement. Its distinguishing position is European infrastructure and European data handling, not simply a European corporate address. AhaSend is transactional infrastructure. It does not provide the contact, campaign, segmentation, or marketing-automation layer. That focus is an advantage when you want only an email delivery API and a second subscription when the product begins sending newsletters. ## 7. MailerSend: a small free tier with visual templates MailerSend includes 500 emails per month, one sending domain, one template, one webhook, and a drag-and-drop editor. The free account is also limited to 100 daily API requests, which can constrain an integration before the monthly message allowance does. It is a good evaluation path when non-developers need to edit transactional templates. The $7 monthly Hobby plan raises the allowance to 5,000 messages, but still carries one-day activity history, one domain, and a 1,000-request daily API ceiling. ## 8. Mailgun: a mature API with a testing-sized free plan Mailgun’s permanent Free plan allows 100 emails per day with REST and SMTP sending, tracking, webhooks, one sending domain, and one inbound route. It is one of the more mature API products and offers US and EU options. The constraint is one day of log retention on Free and Basic. If a customer reports a missing message after a weekend, the provider history may already be gone. Copy signed delivery events into your own durable ledger or choose a plan with enough retention for your support cycle. ## 9. Postmark: best free plan for evaluating production operations Postmark’s permanent developer tier includes only 100 messages per month, but keeps 45 days of activity and exposes the same core transactional model you would use after upgrading. Basic begins at $15 per month for 10,000 messages. Choose it when the free tier is for integration and deliverability evaluation rather than carrying a live product. Its separation of transactional and broadcast streams, searchable history, and operational focus are worth more than a large free allowance to many support-heavy applications. ## How to evaluate a free email sending API - Confirm the offer is permanent. Record the expiration date if it is actually a credit or trial. - Convert monthly and daily caps into your peak hour and peak day, not only an average month. - Check whether one message to multiple recipients consumes one unit per recipient. - Compare sending domains, API keys, webhooks, templates, users, and API requests—not only emails. - Match activity retention to the oldest delivery question your support team must answer. - Verify whether inbound email, attachments, scheduling, and batch endpoints are included if you need them. - Read the region, retention, subprocessor, and deletion documentation for message content and event data. - Price the first paid tier now; a generous free plan can lead to an expensive step at message 3,001. - Test domain authentication, webhook signatures, bounces, complaints, suppression, timeouts, and retries before production. ## Free email API does not mean browser-safe email API A free API key is still a privileged credential. Do not embed it in frontend JavaScript, a mobile application, or a public repository. A browser should request a narrow application action from your server—such as resend my verification email—and server-only code should choose the recipient, sender, template, and provider credentials. ### Safe boundary for a free email API ```text BROWSER MAY REQUEST SERVER MUST OWN resend my verification API key submit this contact form fixed From and To policy send my receipt again recipient authorization template and escaping rate limits and abuse checks idempotency and retry policy delivery-event processing Never expose { apiKey, arbitraryTo, arbitraryFrom, arbitraryHtml } to an unauthenticated client. ``` ## Frequently asked questions ## What is the best free email API for developers? Resend is the strongest general recommendation for a modern transactional integration. Mailjet offers more free monthly volume, Email Bump is stronger when campaigns and flows should share the same account, Mailtrap is strongest for staging safety, AhaSend is the clearest European option, and Postmark is strongest when long history matters more than allowance. ## Is there a free API to send email without a daily limit? Email Bump, Maileroo, and AhaSend publish monthly allowances without the plan-level daily ceilings used by Mailjet, Mailtrap, Resend, MailerSend, and Mailgun. Providers still enforce abuse, reputation, API-rate, and verified-domain controls, so no daily plan cap does not mean unlimited burst traffic. ## Can I use a free email API in production? Yes, if its peak limits, history, support, regional handling, and recovery model meet the application’s needs. Treat the provider like production infrastructure even when the invoice is zero: use a verified domain, signed webhooks, a durable message ledger, suppression handling, monitoring, and a tested paid upgrade path. ## Start with 5,000 contacts and 5,000 emails Use the transactional API, SMTP, inbound email, campaigns, segments, and automated flows on one permanent free plan. Verify your domain when you are ready to send beyond testing. [Create a free account](https://emailbump.com/signup) ## Go from shortlist to implementation - [Email API buyer's guide](https://emailbump.com/blog/email-api) — Compare provider architecture, deliverability, pricing, and operational tradeoffs. - [Send email with REST](https://emailbump.com/blog/send-email-rest-api) — Make the first request, then add safe retries, a durable outbox, and webhooks. ## Sources - [Email Bump pricing](https://emailbump.com/pricing) - [Mailjet email API](https://www.mailjet.com/products/email-api/) - [Mailtrap pricing](https://mailtrap.io/pricing/email-api/) - [Resend pricing](https://resend.com/docs/knowledge-base/what-is-resend-pricing) - [Maileroo free email API](https://maileroo.com/free-email-api) - [AhaSend free email API](https://ahasend.com/free-email-api) - [MailerSend plans and limits](https://www.mailersend.com/help/plans-features-and-limits) - [Mailgun pricing](https://www.mailgun.com/pricing/) - [Postmark pricing](https://postmarkapp.com/pricing) - [Twilio SendGrid pricing](https://www.twilio.com/en-us/products/email-api/pricing) - [Amazon SES pricing](https://aws.amazon.com/ses/pricing/)