The Do-Not-Disturb service (DND) allows Telecom customers to opt out of receiving promotional or notification messages from 3rd Party like Bulk SMS, VAS promos, etc.

By default, ALL MTN users are on DND unless they opt out.

The networks charge extra to deliver SMS to numbers with active DND service. Sometimes the message Sender ID may be changed to rUPDATE, rNOTIFY, INFINITI etc or even a Phone Number.  Read More... 

This button will only works on Mobile Devices.
You can Send an SMS on your phone containing TXT GREENSPEK to this number 55509