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# Email API now supports idempotency.

Passing the `IdempotencyKey` in the[ transactional email](https://developers.sendinblue.com/reference/sendtransacemail) 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

* [Send a transactional email](https://developers.sendinblue.com/reference/sendtransacemail)

```json
curl --request POST \
     --url https://api.sendinblue.com/v3/smtp/email \
     --header 'Accept: application/json' \
     --header 'Content-Type: application/json' \
     --data '
{
     "sender": {
          "name": "Mauricio",
          "email": "mauricio@sendinblue.com"
     },
     "to": [
          {
               "email": "mauricio2@sendinblue.com",
               "name": "Mauricio2"
          }
     ],
     "headers": {
          "idempotencyKey": "b52dbf-81dd-4a08-b807-085c" -----> New attribute 🎉🎉🎉 !
     },
     "subject": "This is a unique email",
     "templateId": 1
}
'
```

## Unicode option on all SMS endpoints

It's now posible to define special characters as non-unicode. Whenever the flag is set to `false` any unicode characters in the message payload will be converted to their english equivalents.

Example characters that are considered unicode\
À  â È Ê ê Ë ë Î î Ï ï Ô ô Œ œ Ù Û û Ÿ ÿ ç

Endpoints supporting this change:

* [Transactional SMS](https://developers.sendinblue.com/reference/sendtransacsms)
* [Campaign SMS](https://developers.sendinblue.com/reference/createsmscampaign-1)

```json
{
     "unicodeEnabled": true,
     "name": "RecipientName",
     "sender": "Sendinblue Inc.",
     "content": "Message body containing unicode characters À Â â È Ê"
}
```