Default [Q] Android Developers Not able to send messages in a group

Hello Friends,
I have brought Samsung Galaxy Core recently. I am getting a problem in sending a message to my group of contacts.

I have created a group of 40 people which I want to send a message to all of them, but when I am trying to select all people in a group I am geeting a message " 10 contacts available only".

Can someone tell me how to get rid of this as I want to send a message to all people in a group created.

Thanks
Vikram Deep Singh