Error : Mailjet API v1
When you connecte Mailjet to DeliPress you may encounter an error. It’s because you are in API version 1 and DeliPress requires API version 3. Sadly there is no way to switch to version 3 without contacting Mailjet.
In this case, contact the Mailjet support and ask them to migrate your account to API version 3.
You can also create a new account and transfer your datas.