使用sock技术发邮件，无需服务器支持。速度快！！
代码如下:
function send_mail($to,$subject,$body)
{
/////////////Smtp信息，可以修改成你的，//////////
$loc_host = "longbill"; //发信计算机名，可随意
$smtp_acc = "longbill.mail"; //Smtp认证的用户名，
$smtp_pass = "longbill"; //Smtp认证的密码，
$smtp_host = "smtp.163.com"; //SMTP服务器地址，
$from = "longbill.mail@163.com"; //要与smtp信息对应 ,否则会失败
/////////////Smtp信息完//////////////////////////////////
$headers = "Content-Type: text/plain; charset=/"gb2312/"/r/nContent-Transfer-Encoding: base64";
$lb="/r/n"; //linebreak
$hdr = explode($lb,$headers); //解析后的hdr
if($body)
{
$bdy = preg_replace("/^/./","..",explode($lb,$body));
}//解析后的Body
$smtp = array(
//1、EHLO，期待返回220或者250
array("EHLO ".$loc_host.$lb,"220,250","HELO error: "),
//2、发送Auth Login，期待返回334
array("AUTH LOGIN".$lb,"334","AUTH error:"),
//3、发送经过Base64编码的用户名，期待返回334
array(base64_encode($smtp_acc).$lb,"334","AUTHENTIFICATION error : "),
//4、发送经过Base64编码的密码，期待返回235
array(base64_encode($smtp_pass).$lb,"235","AUTHENTIFICATION error : "));
//5、发送Mail From，期待返回250
$smtp[] = array("MAIL FROM: <".$from.">".$lb,"250","MAIL FROM error: ");
//6、发送Rcpt To。期待返回250
$smtp[] = array("RCPT TO: <".$to.">".$lb,"250","RCPT TO error: ");
//7、发送DATA，期待返回354
$smtp[] = array("DATA".$lb,"354","DATA error: ");
//8.0、发送From
$smtp[] = array("From: ".$from.$lb,"","");
//8.2、发送To
