In 2015 Telstra launched a beta of their SMS Messaging API (v1) and fmSMS was one of the first commercial solutions to support the Telstra API. Last year Telstra released v2 of the Messaging API with many new features including the provisioning of dedicated numbers and Webhooks. At the same time Telstra announced that they were deprecating the v1 SMS API and that it would be be switched off at the end of May, 2018.
If you are using fmSMS with the v1 Telstra SMS API you can download the latest version of fmSMS which was updated last year to support the v2 API. You can get more information about the v2 Telstra Messaging API here.