User need to follow below steps in order to send SMS from the Contacts object:
Step 1:
System allows user an option to send bulk message to the selected Contact as available in the contacts list.
This can be done through below way:
- Click the Contacts tab. 
- Click on Recently Viewed Contacts drop down. 
- Select all check boxes from where the message is to be sent as shown. 
Step 2:
- Click the blue drop down arrow on top right corner of the page (or directly click Send Bulk SMS button if drop down not available). 
- Then click the Send Bulk SMS button. 
Step 3:
When clicked on Send Bulk SMS button user will be navigated to Send SMS page.
User needs to select a template or enter the Message in the given text area.
Then click the Send button.

Success message will be displayed once the message is sent.
Note: Below alert will be displayed if user doesn't select above check boxes .
Click Back button to go the previous page.
In this way user can send Bulk messages using Contact or any other salesforce object.
