FrontlineSMS was originally developed to allow mass-messaging in places without Internet access. FrontlineSMS versions 1.6 and later support Clickatell and IntelliSMS messaging services. Messages sent this way are generally sent much faster and can be more affordable than sending through an attached mobile phone or modem, but you do need to ensure that you have set up an account and purchase messages upfront with a credit card.

For more information about configuring and using online aggregators, see About SMS Internet Services in the online Help.

If your Clickatell test messages are failing to send, you might also want to try different number formats for the messages.  For example, add the +xx international code if you haven’t tried, or remove it if you have.