Even when a customer has been enrolled it's still possible for a SMS or Push Notification to be sent, but not be successfully delivered. This can be caused by SMS Gateway issues, or mobile numbers becoming invalid over time. As a result of this, it’s also possible for the number of customers who were contacted to be lower than the number of customers enrolled.
In the example image provided below, we can see that while the campaign initiator was prepared to communicate with a maximum of 7,576 customers, by the time the campaign started to enroll customers, only 7,032 were still eligible to be communicated with, and of these, only 6,966 actually received the SMS or Push Notification.
