织梦dedecms自定义表单发送邮件(QQ、163、126邮箱)的方法

$mailtitle = "{$diy->name}--留言通知";
$mailbody = '';
foreach($diy->getFieldList() as $field=>$fieldvalue)
{
$mailbody .= "{$fieldvalue[0]}:{${$field}}\r\n";
}
$headers = "From: ".$cfg_adminemail."Reply-To: ".$cfg_adminemail;
if($cfg_sendmail_bysmtp == 'Y' && !empty($cfg_smtp_server))
{
$mailtype = 'TXT';
require_once(DEDEINC.'/mail.class.php');
$smtp = new smtp($cfg_smtp_server,$cfg_smtp_port,true,$cfg_smtp_usermail,$cfg_smtp_password);
$smtp->debug = 0;//发送不成功把0改成1，再提交看错误信息
$smtp->sendmail($cfg_shoujianren,$cfg_webname ,$cfg_smtp_usermail, $mailtitle, $mailbody, $mailtype);
}
else
{
@mail($cfg_shoujianren, $mailtitle, $mailbody, $headers);
}

$headers = "From: ".$cfg_adminemail."Reply-To: ".$cfg_adminemail;

$mailbody = mb_convert_encoding($mailbody, "GBK", "UTF-8");