As from January 2015, your ST+ SIM card can make send and receive SMS / text messages in the normal way.
In order to do this, you must select just one single 'Assigned' inbound DID / number (as oppose to several which can be used / set if SMS is not required).
Some number ranges are not SMS enabled: e.g. 0203475 and 0203745 for example.
We will also introduce a feature in to record SMS / text messages in the same way that calls can be recorded.