Delayed delivery can have several different reasons. It is possible that the phone was switched off at the time of sending, in which case we will try to redeliver the message for several days. If the number and content are not filtered out and the handset is not off/out of network range, most networks will try for 48-72 hours to deliver the message. If you have set a validity period on your SMS we will retry during this time only.
It is also possible that the delay was caused by the network itself. Most of the time delayed delivery is related to a disconnect between the carrier and the handset. A reset of the phone re-establishes the connection and allows the SMS to be delivered.
If you encounter this issue more often or see that this is affecting multiple numbers, we can escalate this with the supplier. We need the following information from your side:
- At least two affected recipient number (we welcome more samples too!)
- Date and timestamps (including time zone) when the messages were sent and when they were delivered on the phone.