You need to be a regd member of www.smsgatewaycenter.com. Install this simple plugin and start sending bulk sms. This gateway only supports India.
This plugin are used to send sms world wide.
Send SMS to any Indian number from any country.To start Recharge or request for First Free 25 Credits via Support
The UltimateAdminSms Plugin allows WordPress Administrators to send SMS to their users through the ultimatesmsapi.tk SMS Gateway.
Send SMS allows you to send Bulk SMS from your wordpress interface. Management and Import of the mailing list. Compatible with the webservice OVH-sms.
The SMSGlobal SMS Plugin allows WordPress Administrators to send SMS to their users through the SMSGlobal Gateway.