Pokud máš chytrý mobil s Androidem tak:

int pocetSMS = 100;

for (int i=1;i<pocetSMS; i++)
{
 sendSMS("123456", "Hi You got a message!");
}

private void sendSMS(String phoneNumber, String message) {
    SmsManager sms = SmsManager.getDefault();
    sms.sendTextMessage(phoneNumber, null, message, null, null);
}