SMS is not supported. Most mobile phones now can browse the internet which is much easyer for the
users to login to their accounts and update or post their ads and browse their web normal.
What you can do if you want is to create another theme for your site for mobile browsers and
reduce the graphics and the html code in that theme so it can load faster and cost less for the mobile
users, of course this will take you some time to do this light customization.