Please note that Acelle Demo was used for the purpose of this tutorial.

In order to add a new Elastic Email server in Acelle, navigate to Sending>Sending Servers:

On the following screen, use the New Server button to add Elastic Email integration to your Acelle installation:

Here you can choose either API or SMTP integration with Elastic Email. For the purpose of this tutorial, Elastic Email SMTP will be demonstrated (The Elastic Email API integration will require you to just input your API Key):

On the resulting screen, you will have to provide your API Key and SMTP credentials. Both these details can be found on the Elastic Email Settings screen. When you are done, just hit the "Save" button.

If the provided credentials are correct, the server name will appear as Active:

Now you are free to test your connection. As soon as you add your Sending Identity (Elastic Email Domain) to this setup, you will also be able to send a test email.