Technical Level: Easy
From time to time, a clinic may report that they are unable to send SMS text messages to a particular patient - but that messages seemingly succeed when sent to every other patient.
In this case, it is sometimes helpful to widen the filter to include several months of activity from the patient's cell nuber to the clinic's Twilio alias. What you're seeking is some occasion on which the patient texted back to the clinic what is commonly referred to as a 'reserved SMS keyword'.
These reserved keywords are supported by most text carriers in an effort to provide their customers with the ability to 'black-list' any caller who might be spamming or annoying them by the use of a keyword, e.g., 'STOP' or 'CANCEL' (others commonly supported are: 'STOPALL', 'UNSUBSCRIBE', 'END' or 'QUIT'). Once the patient has texted one of these keywords back to the the clinic (and possibly even inadvertently, in the case that the patient was attempting to cancel an appointment, not all future communication from the clinic), no further communication can/will occur between the clinic and patient unless/until the patient texts 'START' or 'YES' from their phone number to the clinic's alias text number. NOTE: it must be to the alias number configured in Clockwise for the clinic, NOT the clinic's actual office phone number.
Further documentation can be found at this link:
If you are viewing this as a Clockwise clinic, you will not have access to the actual SMS logs. Please contact Clockwise Support at firstname.lastname@example.org or call 1-800-729-1363 for further assistance.