I am trying to create a form that uses the mail() function to send the form variables to my email. I works great on my local host but when I uploaded it to my server it will not send.

$Fname = stripslashes($_POST['FirstName']);
		 $Lname = stripslashes($_POST['LastName']);
		 $from = "$Fname $Lname";
		 $recipient = "mcglynn@aserty.com";
         $subject = "Service Request";

$msg = "Message sent by $from\n";
         $msg.="\nAddress: ".$_POST['Address'];
		 $msg.="\nCity: ".$_POST['City'];
		 $msg.="\nProvince: ".$_POST['Province'];
		 $msg.="\nPostalCode: ".$_POST['PostalCode'];
		 $msg.="\nTelephone: ".$_POST['Telephone'];
		 switch($_POST['Service']){
            case 'ADSL_Standard':
               $msg.="\nI would like to sign up for: ADSL Standard ";
               break;
            case 'ADSL_Premium':
               $msg.="\nI would like to sign up for: ADSL Premium ";
			  break; 
			case 'ADSL_Standard_dry_loop':
               $msg.="\nI would like to sign up for: ADSL Standard Dry Loop";
			  break;
			case 'ADSL_Premium_dry_loop':
               $msg.="\nI would like to sign up for: ADSL Premium Dry Loop";
			  break;
			case 'Unlimited Dial-Up':
               $msg.="\nI would like to sign up for: Unlimited Dial-Up";
			  break;
			case 'Student Unlimited Dial-Up':
               $msg.="\nI would like to sign up for: Student Unlimited Dial-Up";
			  break;
			case 'Snowbird Unlimited Dial-Up':
               $msg.="\nI would like to sign up for: Snowbird Unlimited Dial-Up";
			  break;
			case 'Connected Minutes Dial-Up':
               $msg.="\nI would like to sign up for: Connected Minutes Dial-Up";
			  break;
			  } 
         $options=$_POST['options'];

if (mail($recipient,$subject,$msg)){
            echo "<p>Thanks for your order!</p>";
            echo nl2br($msg);
         } else
            echo "An unknown error occurred.";
      }
   }