Email API now supports idempotency.

Passing the IdempotencyKey in the transactional email headers now allows you to be sure the request will be processed only once and that not repeated emails will be sent to your recipients mailbox.

The idempotencyKey needs to be a unique identifier every time it is passed. We recommend to use a UUID v4 for this purpose.

The TTL for the idempotencyKey is 15 minutes.

Endpoint supporting Idempotency

curl --request POST \
     --url \
     --header 'Accept: application/json' \
     --header 'Content-Type: application/json' \
     --data '
     "sender": {
          "name": "Mauricio",
          "email": "[email protected]"
     "to": [
               "email": "[email protected]",
               "name": "Mauricio2"
     "headers": {
          "idempotencyKey": "b52dbf-81dd-4a08-b807-085c" -----> New attribute πŸŽ‰πŸŽ‰πŸŽ‰ !
     "subject": "This is a unique email",
     "templateId": 1