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
$smtp[] = array("To: ".$to.$lb,"","");
//8.1、发送标题
$smtp[] = array("Subject: ".$subject.$lb,"","");
//8.3、发送其他Header内容
foreach($hdr as $h) {$smtp[] = array($h.$lb,"","");}
//8.4、发送一个空行，结束Header发送
$smtp[] = array($lb,"","");
//8.5、发送信件主体
if($bdy)
{
foreach($bdy as $b)
{
$smtp[] = array(base64_encode($b.$lb).$lb,"","");
}
}
//9、发送“.”表示信件结束，期待返回250
$smtp[] = array(".".$lb,"250","DATA(end)error: ");
//10、发送Quit，退出，期待返回221
$smtp[] = array("QUIT".$lb,"221","QUIT error: ");
//打开smtp服务器端口
$fp = @fsockopen($smtp_host, 25);
if (!$fp) echo "<b>Error:</b> Cannot conect to ".$smtp_host."<br>";
while($result = @fgets($fp, 1024))
{
if(substr($result,3,1) == " ") { break; }
}
$result_str="";
//发送smtp数组中的命令/数据
foreach($smtp as $req)
{
//发送信息
@fputs($fp, $req[0]);
//如果需要接收服务器返回信息，则
if($req[1])
{
//接收信息
while($result = @fgets($fp, 1024))
{
if(substr($result,3,1) == " ") { break; }
}
if (!strstr($req[1],substr($result,0,3)))
{
$result_str.=$req[2].$result."<br>";
}
}
}
//关闭连接
@fclose($fp);
if ($result_str==""){return "发送成功!!";}else {return $result_str;}
}