PHP mail function sends mail and garbled code solution

<?php
/**
 * mail函数发送邮件 乱码问题
 * 整理 by http://bbs.it-home.org
*/
$to = 'sales@zui88.com';
$subject = "=?UTF-8?B?".base64_encode('程序员之家，欢迎大家的光临。')."?=";
$message = "
用户姓名：{$_POST['name']}\n
用户邮箱：{$_POST['email']}\n
用户电话：{$_POST['contact']}\n
留言内容：{$_POST['content']}
";
$headers = 'From: test@jbxue.com' . "\r\n" .
'Reply-To: admin@jbxue.com' . "\r\n" .
'X-Mailer: PHP/' . phpversion();
$headers .= 'Content-type: text/html; charset=utf-8' . "\r\n";

mail($to, $subject, $message, $headers);
?>