This article illustrates how to enable the Delivery Reports on SENT messages

Whit this procedure you will be able to receive on the Foxbox the DLRs (Delivery Reports) for the SMS you send.
This is an SMS that the air carrier will send you back to notify the delivery status of your previously sent SMS. It is a common feature when you need to be 100% sure that an SMS has reached the destination.

Firstly you have to place the script report.sh (available here) in /etc/sms/scripts/. Be sure that it has enough priviledges to be executed by the system.
Moreover, you have to create a new folder in /mnt/flash/spool/ called "report". Please set to this folder the same priviledges of the other ones.

Then you have to edit the eventhandler (in /etc/sms/scripts/) inserting these rows:

if [ "$1" = "REPORT" ]; then 
     /etc/sms/scripts/report.sh
fi 

Finally you have to edit the SMS engine configuration (in /etc/smsd.conf). Between the row with "rtscts = no" and the one with "cs_convert = yes", insert this one:

report = yes

Now the procedure is complete. After a system reboot, try to send an SMS, and you should receive a notification message in the /mnt/flash/spool/report/ folder with the same name as the sent message.
Use it to apply a check to your scripts!