Tracking undelivered SMS Messages


There are several reasons why an SMS Message might not be delivered. These include the mobile phone being turned off, or out of radio range. There are also reasons that are related to the mobile phone carrier that the patient/client is using. This article describes these reasons, and features within Capable 21C to track and manage undelivered SMS Messages.

Underlying challenge

When an SMS Message is transmitted using Capable 21C, the message follows a complex path.

  • Firstly, the message is sent to Capable Software’s wholesale SMS Messaging provider.
  • Then, the message is sent on to an SMS Messaging gateway.
  • Then, the message is sent to the carrier of the mobile phone. /li>
  • At this point, the message may be re-directed to another carrier if the owner of the phone has changed carrier, but retained their original phone number.
  • The carrier holds the message until it can contact the mobile phone and deliver the SMS. If the message remains undelivered for a certain amount of time, it will be abandoned. This amount of time varies from carrier to carrier, but is typically between 24 and 72 hours.
  • SMS Messages can be delayed at any of these stages. Furthermore, at some of these stages, SMS Messages can be declined or rejected. Capable 21C reports to the operator if it can successfully complete the first transmission step. If the operator receives confirmation from Capable 21C that the SMS Message has been sent, this only means that the first step of the process has been completed.

    Capable 21C has the ability to check with the wholesale SMS Messaging provider on the status of the message, but in doing so, only limited information can be retrieved about the actual status of the message. Exploiting this feature gives an office the ability to reasonably closely determine whether the message has been delivered.

    Note that to retrieve information about the status of an SMS Message, Capable 21C requests that information from the wholesale SMS Provider, who, in turn requests the information from the gateway, who in turn requests the information the carrier. At any of these stages, the information that is returned might not be completely consistent with the information returned by other carriers. For example, if a mobile phone is turned off, but the carrier has confirmed that it has received the SMS Message and intends to deliver it to the phone as soon as the phone is turned back on, some carriers will report the status of the message as ‘Delivered’. Other carriers report the status of the message as ‘Submitted’. This may be misleading, as in this particular scenario, the message has not actually been delivered to the phone. Having said that, any message with a status of ‘Queued’ or ‘Submitted’ has definitely not been delivered to the phone yet.

    Capable Software Pty Ltd recommends use of the ‘Track unsent SMSes’ feature to monitor the status of SMS Messages. If a message remains in the ‘Submitted’ state for any extended period of time, the office should consider either resending the message with High Priority (which carries a greater expense), or contacting the patient/client by other means.


    To exploit the Track Unsent SMSes feature, follow these steps:

  • Click the Action Other Tasks button on the Things To Do list.
  • Click the Setup Periodic tasks option.
  • Create a new periodic task by clicking the New Task button.
  • On the list of available task types, scroll to the bottom and select ‘Track unsent SMSes’
  • Switch to the Frequency tab, and set the frequency to be daily.
  • Switch to the Next Activation tab, and set the date and time of next activation to be a short amount of time after the usual transmission of SMSes. For example, if SMSes are normally transmitted at 8:00am, set the next activation time to be 8:30am.
  • Close the Task Properties window.
  • If SMSes are sent at multiple times throughout the day, it might be beneficial to repeat steps 3 to 7 using a slightly different name for the periodic task.
  • When the Track Unsent SMSes appears on the Things To Do list, follow these steps:

  • Click on the Track Unsent SMSes option on the Things To Do list to see which SMSes have not been delivered.
  • As soon as this option is selected, Capable 21C will contact the wholesale SMS Message provider via the Internet to update the status of messages. Note that this requires an active internet connection, and will take a few moments to complete. Note also that this feature will only monitor the last 500 SMS Messages sent.
  • For each SMS that displays a status of Queued or Submitted, click once on the SMS to elect how to deal with it. The available options include ‘Client Info’, ‘Remove from List’, ‘Resend’ and ‘Resend with high priority’.
  • Detailed Information

    More detailed technical information can be obtained about undelivered SMS Messages from the SMS Setup screen. The audit log shows specific information about the status of the message. The following codes are used:

    -0- indicates that the message has been queued by the wholesale SMS Message Provider, but has not been forwarded to the gateway yet.

    -1- indicates that the message has been submitted to the carrier, but has not been delivered yet. If the client/patient’s mobile phone has been changed to a different carrier since the original phone number was issued, messages may remain in this state for a long period of time. Certain carriers in Australia do not forward messages to the correct carrier automatically.

    -2- indicates that the message is undelivered.

    -3- indicates that the carrier has accepted the message, and has either already delivered it to the phone, or intends to deliver it to the phone as soon as the phone comes back into radio range. If a message is in this state, it will be delivered to the phone (as long as the phone comes back into radio range within 24 hours).

    -4- indicates that the message expired before it could be delivered. This will occur if a mobile phone is left off (or outside radio range) for too long.

    -8- indicates that the message was rejected by the gateway, or by the carrier.

    ‘Can’ is a special status used by Capable 21C to indicate that the message will no longer be tracked by the Unsent SMSes window. This status is used by Capable 21C if a message is removed from the list by an operator, or if the original message is resent. In the case when a message is resent, the resent message will be tracked, and the original message will be given the status of ‘Can’.

    Note that for some statuses, a date and time may be indicated as well as the status (eg -3-24/5/2007 8:37AM). The first three characters indicate the status. The remainder of the status entry indicate when the message entered this state.

    This knowledge resource is designed for use on a Windows (tm) XP system operating at a screen resolution of 1024x768 or better. Windows Media Player must be installed for this training resource to operate correctly.

    Copyright 2008 Capable Software Pty Ltd

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