I'm trying to set up an SMS campaign using Clickatell, but it's not working. On clickatell, I have purchased some credit, and set up a http API. I've then pasted this API key into Zoho Marketing. I tested the API in clickatell and manage to setup my phone number as a test phone. I have the SMS setup to trigger when someone is added to the list - nothing! 

Anyone else having issues with this?