Hello and welcome to the Mailjet's Email API!
Mailjet APIs are built using RESTful principles, featuring clear and consistent resource-oriented URLs for easy integration. It uses standard HTTP methods like GET, POST, PUT, and DELETE to interact with resources, and returns structured JSON for all requests and responses—including errors. Each API request is made over HTTPS to a versioned endpoint, ensuring secure and predictable communication. HTTP status codes are used to indicate the success or failure of requests, making error handling straightforward for developers.
In the Mailjet API, all PUT requests behave like PATCH requests. The update will affect only the specified properties. The other properties of an existing resource will neither be modified, nor deleted. It also means that all non-mandatory properties can be omitted from your payload.
The Mailjet API is spread under 3 versions.
- V3: This includes all REST API resources and one transactional API resource.
- V3.1: A second transactional API which includes advanced error management.
- V1: The Content API is under V1
One of the main differences between the V3 and V1 versions is a change in authentication:
- V3s are using basic authentication with your public and secret API keys.
- V1 leverages a token authentication.
The URL paths for every API resource can be found in the API reference under the respective resource name.
Mailjet applies rate limits to API requests and returns 429 Too Many Requests when a limit is reached. Mailjet does not publish rate-limit figures.
Your integration should handle 429 responses with a retry mechanism: wait before retrying the affected request, use exponential backoff with jitter, and limit retry attempts.
See Rate Limits for retry guidance and ways to reduce request pressure.