Message follow up - MikeBlyth/mission_database GitHub Wiki

Every message keeps a list of each intended recipient and whether they have received the message. A message is marked as received when (a) the SMS gateway notifies the system that the message was delivered to the mobile phone or (b) the recipient replies to the message. For the second method to work, the message needs to include an ID number generated by the system so that replies can reference that number. Note that some SMS gateways (e.g. Clickatell) can inform the sender that the message was delivered, while others (e.g. Twilio) currently cannot.

You can view the delivery status of a message from the status summary column in the messages listing. For details, click on the "Sent to" column. This will display a list of all the intended recipients with the status of each one.

Limitation/needs improvement: The way the status is determined varies with the way the message was sent and the gateways used. For example, an email with a bad address may not be detected as an error, while an SMS message to a non-existent number probably will be. Delivery of email is not generally detected. Even if a message is shown as delivered, that does not mean that it was opened or read. When it is important to be sure that a message was read, the only sure method is to request confirmation. In the example above, the message was sent to 82 people, but the status summary shows 4 deliveries and nothing else. Apparently the other 78 messages went to the email gateway without error, but there is no way to know whether they were delivered.

This feature allows you to send a follow-up message only to the people who have not received or responded to the original message. To access it, just click on the message's "Follow up" link in the main message listing. A default follow-up message is already shown; change it as needed and click the Send button to broadcast the follow-up.