Add a Clickatell gateway
After creating a Clickatell account on the Clickatell website you also have to add an HTTP connection to the Clickatell account. You end up with an HTTP API ID, user name and password that must be used in the wizard page.

After you set up the Clickatell account and sent your first messages you will notice that the sender id of the messages is a +44xxxxxxxx number. Clickatell supports using your own numeric or alphanumeric sender id, but to prevent id spoofing you have to register the sender id list before you can use them.
Log in to Clickatell Central and select My Settings and Manage Sender ID’s. Here you can add and delete id’s to your sender id list. Since the id’s are approved manually it can take some time before you can use them. You may use existing mobile phone numbers as the sender id if you want the replies to go to your mobile phone.
In the Clickatell Gateway Properties you must add the approved sender ID list. On the Advanced tab page click on the ApprovedFromList button and fill in the sender id list, one sender id on each line. You can also specify the DefaultFrom value, this sender id will be used if the sender has not specified the sender id or if that sender id is not in the approved list.