Background image & content on the background image is not visible in mobile when email is sent to gmail using asp.net C# windows application

mailbody += "<div style="width: 760px;height:570; margin: 0 auto;background-image: removed(cid:Presentation.jpg); border: 1px solid #333"><br /><table width="760" border="0" cellspacing="0" cellpadding="0"></table><br /><br /><table width="760" border="0" cellspacing="0" cellpadding="0"><tr><td style="font-size:26px;  color:#fff;font-family:Algerian;"><center><b>Hello google</b></center></td></tr></table></div>";