For all iPhone users who miss SMS delivery notification, here is a simple trick to make it work on your iPhone.
Just enter these special characters before your message and you will get notification as soon as it gets delivered.
Since this is a feature of the cell carrier, this trick will work on other phones as well. The carrier will also strip out the special characters when it delivers the message to the recipient.
If you know codes of other carriers, please mention it in the comments. Thanks!