If a patient replies to a text message you sent them it will automatically appear in your workstation inbox. Be sure that patients send text messages by responding to a text message you sent to them initially. This conversation will have a "conversation lock" on it, allowing them to reply to you successfully.
Short code technology requires a keyword so it knows where to send the message. If they composed a new text message in their cell phone and did not use a keyword as the first word in the text, the message will be stuck in the cloud.
A great way to test this is to send them a message when they are in the office to ensure that both parties are getting the messages.
Please feel free to reach out to firstname.lastname@example.org if you have any additional questions!