ok now try this

PHP Code:
$userfile_type "application/sql";

//MIME code
$boundary "b" md5(uniqid(time()));
$mime_header "Content-type: multipart/mixed;";
$mime_header .= "boundary = {$boundary}\r\n\r\n";
$mime_header .= "This is a mime encoded message.\r\n\r\n";

//First the regular message
$mime_message .= "--{$boundary}\r\n";
$mime_message .= "Content-type: {$userfile_type}\r\n";
$mime_message .= "Content-Type: text/plain; charset=\"iso-8859-1\"\r\n";
$mime_message .= "Content-Transfer-Encoding: 7bit\r\n\r\n";
$mime_message .= "{$message}\r\n";

//Now the attachment
if(!($fp = @fopen($filename"rb"))){
$error "Can't open file";
echo 
$error;
exit;
}
$attach fread($fpfilesize($filename));
$attach chunk_split(base64_encode($attach));
$file_name basename($filename); // gets basename of file

$mime_message .= "--$boundary\r\n";
$mime_message .= "Content-Type: $userfile_type; name=\"{$file_name}\"\r\n";
$mime_message .= "Content-Transfer-Encoding:base64\r\n ";
$mime_message .= "Content-Disposition: attachment; filename=\"{$file_name}\"\r\n\r\n";
$mime_message  .= "\r\n\r\n$attach\n";
$mime_message .= "--{$boundary}--\r\n";

mail($email"Database Backup of ".$dbname." At ".date("H:i:s"), $mime_message $mime_header); 
in order to send text you also have to have the "Content-Transfer-Encoding: 7bit" and you also forgot the attachment line. so try that an dlet me know how you get on.

look at what I changed and added