A free email API can work for an AI-built app when the app has a secure backend and the provider supports the messages you need. Emailer API is a fit to consider for approved transactional emails with guided setup included. Choose by the actual sending workflow and current capacity, not just the word free.
Three emails every growing business needs
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Start with the customer action
Write down the first action that should trigger an email: an account verification, password reset, security alert, paid order, payment receipt or appointment confirmation. Emailer API supports these through a fixed template catalog. It does not currently accept arbitrary message bodies, marketing broadcasts, attachments or multiple recipients through Cc and Bcc.
Example: a booking app needs to confirm a real appointment. That is a different integration from sending a promotional newsletter to every subscriber. If newsletters or unrestricted layouts are central to your product, evaluate a provider that supports those requirements before committing.
Check what your AI app builder actually hosts
A generated interface is only one part of the integration. Sending keys and requests need a secure server-side home. The event source depends on the selected email: account, security and appointment workflows use an application callback backed by your actual records; payment receipts and paid-order confirmations use direct Stripe verification. Ask your coding assistant to identify the path your workflow needs before it adds a send button.
| Requirement | What to check |
|---|---|
| Backend | Secrets and sending requests stay off the browser. |
| Events | Application-verified emails use your actual records and a callback. Receipts and paid orders use an eligible Stripe event. |
| Domain | You control DNS and can host the required callback where applicable. |
| Messages | The approved catalog covers your customer workflow. |
| Capacity | Your peak demand fits both account limits and shared availability. |
Match the event-verification path
For account, security and appointment emails, Emailer API checks a signed application callback on the exact verified sending domain. The callback must query your actual data; a handler that approves every request is not a useful check. For financial receipts and paid orders, the supported verification provider is Stripe.
These are application integration requirements. The fact that an assistant wrote the code does not complete them. There is no implied native integration with every AI app builder.
Understand the free plan before choosing
Free for Life costs $0 per month, without a trial expiry, automatic paid upgrade or paid overages. New accounts start with 100 recipient reservations per UTC day and 3,000 per calendar month. Account and domain checks still apply.
The platform currently shares 1,000 delivery attempts per day, including 50 reserved for identity mail, with attempts at least three seconds apart. Account allowances are ceilings rather than reserved throughput. Use the pricing page and your dashboard to assess a real workload; do not plan a launch burst from the monthly number alone.
Use setup help, then verify one complete workflow
The included assistant helps you choose an email, check domain records, install an approved template and generate a server-side starter. You can do this inside Emailer API without buying another AI account. Optional ChatGPT and Claude connections can use the same saved onboarding progress where the client supports them.
Create the account, choose one customer action and connect it end to end. Validate the exact request, review a real test send and inspect its later outcome before relying on the integration. If you are comparing alternatives, use the linked comparison alongside each provider’s current documentation. A general list of features is not a delivery benchmark.
Common questions
Do I need to move my app to Emailer API?
Your application stays on its host. You connect its backend and verified sending domain to the email service.
Can the assistant finish everything without access to my app?
It can guide setup and generate a starter. You still store secrets securely, connect the event-verification source required by your chosen email and deploy the server-side integration. Application-verified events also need a callback backed by your actual data.
Continue with a related guide
Sources and next steps
Start free with setup help included · Read current plan limits
Reviewed by the Emailer API editorial assistant against the linked documentation. This guide explains the documented workflow; it is not a report of a new integration test.