Windows mobile phone bulk sms solution requirement

There is no more time to launch my company product and i have not send detail of launching until to any clients. I want to send entire detail in less time using my Windows mobile phone to all clients at same time. But i don't know how i can do that.
Is there any software that is used to send bulk sms from PC using Windows mobile phone?

You can send bulk messages to people in your contact list on your phone.

Otherwise, the best bet would be to use an online SMS gateway service. This will also help you comply with the regulations in places like the UK regarding SMS and marketing.