现在很多主机空间都是IIS上执行PHP程序，大多不能直接用mail()发送邮件，有了这个类只要你有注册过邮箱，就可以随意的发送邮件，速度也不慢哦。
//******************************
// smtp.php文件
//
//******************************
<?php
class smtp
{
/* Public Variables */
var $smtp_port;
var $time_out;
var $host_name;
var $log_file;
var $relay_host;
var $debug;
var $auth;
var $user;
var $pass;
/* Private Variables */
var $sock;
/* Constractor */
function smtp($relay_host = "", $smtp_port = 25,$auth = false,$user,$pass)
{
$this->debug = FALSE;
$this->smtp_port = $smtp_port;
$this->relay_host = $relay_host;
$this->time_out = 30; //is used in fsockopen()
#
$this->auth = $auth;//auth
$this->user = $user;
$this->pass = $pass;
#
$this->host_name = "localhost"; //is used in HELO command
$this->log_file = "";
$this->sock = FALSE;
}
/* Main Function */
function sendmail($to, $from, $subject = "", $body = "", $mailtype, $cc = "", $bcc = "", $additional_headers = "")
{
$mail_from = $this->get_address($this->strip_comment($from));
$body = ereg_replace("(^|(\r\n))(\.)", "\1.\3", $body);
$header = "MIME-Version:1.0\r\n";
if($mailtype=="HTML"){
$header .= "Content-Type:text/html\r\n";
}
$header .= "To: ".$to."\r\n";
if ($cc != "") {
$header .= "Cc: ".$cc."\r\n";
}
$header .= "From: $from<".$from.">\r\n";
$header .= "Subject: ".$subject."\r\n";
$header .= $additional_headers;
$header .= "Date: ".date("r")."\r\n";
$header .= "X-Mailer:By Redhat (PHP/".phpversion().")\r\n";
list($msec, $sec) = explode(" ", microtime());
$header .= "Message-ID: <".date("YmdHis", $sec).".".($msec*1000000).".".$mail_from.">\r\n";
&nb
