php使用smtp协议发邮件

php有一个mail()函数，可以用来发邮件，但是在系统里面需要进行详细的配置。如果在windows系统里面还有安装sendmail软件。而且一个服务器上只能统一使用相同是smtp来发送邮件。无法满足更复杂的需求。

网上有一个smtp发邮件的组件，叫jmail，在asp和asp.net里面非常流行这个组件。在php中，也可以使用com对象来调用jmail的功能。不过jmail是一个dll组件，貌似只能在windows里面使用。我们写php的系统，肯定希望在windows或linux上尽可能都能兼容，所以，这个也放弃了。

最后，范围就很小了。只能自己来实现一个smtp发邮件的功能。正好在网上找到一个email.class.php的类。它貌似最早由一个外国人写的，可以完全模拟smtp发邮件。调用时，传递smtp服务器地址、端口、用户名、密码、发件人、收件人、主题、内容、邮件类型等，非常方便。同一个服务器不同的应用，可以同一个应用的不同模块，都可以自由的调用。

代码如下 

<?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\";
$TO = explode(\",\", $this->strip_comment($to));
if ($cc != \"\") {
$TO = array_merge($TO, explode(\",\", $this->strip_comment($cc)));
}
if ($bcc != \"\") {
$TO = array_merge($TO, explode(\",\", $this->strip_comment($bcc)));
}
$sent = TRUE;
foreach ($TO as $rcpt_to) {
$rcpt_to = $this->get_address($rcpt_to);
if (!$this->smtp_sockopen($rcpt_to)) {
$this->log_write(\"Error: Cannot send email to \".$rcpt_to.\"\\n\");
$sent = FALSE;
continue;
}
if ($this->smtp_send($this->host_name, $mail_from, $rcpt_to, $header, $body)) {
$this->log_write(\"E-mail has been sent to <\".$rcpt_to.\">\\n\");
} else {
$this->log_write(\"Error: Cannot send email to <\".$rcpt_to.\">\\n\");
$sent = FALSE;
}
fclose($this->sock);
$this->log_write(\"Disconnected from remote host\\n\");
}
return $sent;
}
/* Private Functions */
function smtp_send($helo, $from, $to, $header, $body = \"\")
{
if (!$this->smtp_putcmd(\"HELO\", $helo)) {
return $this->smtp_error(\"sending HELO command\");
}

#auth
if($this->auth){
if (!$this->smtp_putcmd(\"AUTH LOGIN\",  64_encode($this->user))) {
return $this->smtp_error(\"sending HELO command\");
}
if (!$this->smtp_putcmd(\"\",  64_encode($this->pass))) {
return $this->smtp_error(\"sending HELO command\");
}
}
#
if (!$this->smtp_putcmd(\"MAIL\", \"FROM:<\".$from.\">\")) {
return $this->smtp_error(\"sending MAIL FROM command\");
}
if (!$this->smtp_putcmd(\"RCPT\", \"TO:<\".$to.\">\")) {
return $this->smtp_error(\"sending RCPT TO command\");
}
if (!$this->smtp_putcmd(\"DATA\")) {
return $this->smtp_error(\"sending DATA command\");
}
if (!$this->smtp_message($header, $body)) {
return $this->smtp_error(\"sending message\");
}
if (!$this->smtp_eom()) {
return $this->smtp_error(\"sending <CR><LF>.<CR><LF> [EOM]\");
}
if (!$this->smtp_putcmd(\"QUIT\")) {
return $this->smtp_error(\"sending QUIT command\");
}
return TRUE;
}

function smtp_sockopen($address)
{
if ($this->relay_host == \"\") {
return $this->smtp_sockopen_mx($address);
} else {
return $this->smtp_sockopen_relay();
}
}
function smtp_sockopen_relay()
{
$this->log_write(\"Trying to \".$this->relay_host.\":\".$this->smtp_port.\"\\n\");
$this->sock = @fsockopen($this->relay_host, $this->smtp_port, $errno, $errstr, $this->time_out);
if (!($this->sock && $this->smtp_ok())) {
$this->log_write(\"Error: Cannot connenct to relay host \".$this->relay_host.\"\\n\");
$this->log_write(\"Error: \".$errstr.\" (\".$errno.\")\\n\");
return FALSE;
}

$this->log_write(\"Connected to relay host \".$this->relay_host.\"\\n\");
return TRUE;;
}

function smtp_sockopen_mx($address)
{
$domain = ereg_replace(\"^.+@([^@]+)$\", \"\\1\", $address);
if (!@getmxrr($domain, $MXHOSTS)) {
$this->log_write(\"Error: Cannot resolve MX \\\"\".$domain.\"\\\"\\n\");
return FALSE;
}
//专注与php学习 http://www.daixiaorui.com 欢迎您的访问

foreach ($MXHOSTS as $host) {
$this->log_write(\"Trying to \".$host.\":\".$this->smtp_port.\"\\n\");
$this->sock = @fsockopen($host, $this->smtp_port, $errno, $errstr, $this->time_out);
if (!($this->sock && $this->smtp_ok())) {
$this->log_write(\"Warning: Cannot connect to mx host \".$host.\"\\n\");
$this->log_write(\"Error: \".$errstr.\" (\".$errno.\")\\n\");
continue;
}

$this->log_write(\"Connected to mx host \".$host.\"\\n\");
return TRUE;
}

$this->log_write(\"Error: Cannot connect to any mx hosts (\".implode(\", \", $MXHOSTS).\")\\n\");
return FALSE;
}

function smtp_message($header, $body)
{
fputs($this->sock, $header.\"\\r\\n\".$body);
$this->smtp_debug(\"> \".str_replace(\"\\r\\n\", \"\\n\".\"> \", $header.\"\\n> \".$body.\"\\n> \"));
return TRUE;
}

function smtp_eom()
{
fputs($this->sock, \"\\r\\n.\\r\\n\");
$this->smtp_debug(\". [EOM]\\n\");
return $this->smtp_ok();
}

function smtp_ok()
{
$response = str_replace(\"\\r\\n\", \"\", fgets($this->sock, 512));
$this->smtp_debug($response.\"\\n\");
if (!ereg(\"^[23]\", $response)) {
fputs($this->sock, \"QUIT\\r\\n\");
fgets($this->sock, 512);
$this->log_write(\"Error: Remote host returned \\\"\".$response.\"\\\"\\n\");
return FALSE;
}
return TRUE;
}

function smtp_putcmd($cmd, $arg = \"\")
{
if ($arg != \"\") {
if($cmd==\"\") $cmd = $arg;
else $cmd = $cmd.\" \".$arg;
}
fputs($this->sock, $cmd.\"\\r\\n\");
$this->smtp_debug(\"> \".$cmd.\"\\n\");
return $this->smtp_ok();
}

function smtp_error($string)
{
$this->log_write(\"Error: Error occurred while \".$string.\".\\n\");
return FALSE;
}

function log_write($message)
{
$this->smtp_debug($message);
if ($this->log_file == \"\") {
return TRUE;
}

$message = date(\"M d H:i:s \").get_current_user().\"[\".getmypid().\"]: \".$message;
if (!@file_exists($this->log_file) || !($fp = @fopen($this->log_file, \"a\"))) {
$this->smtp_debug(\"Warning: Cannot open log file \\\"\".$this->log_file.\"\\\"\\n\");
return FALSE;;
}

flock($fp, LOCK_EX);
fputs($fp, $message);
fclose($fp);

return TRUE;
}


function strip_comment($address)
{
$comment = \"\\([^()]*\\)\";
while (ereg($comment, $address)) {
$address = ereg_replace($comment, \"\", $address);
}
return $address;
}

function get_address($address)
{
$address = ereg_replace(\"([ \\t\\r\\n])+\", \"\", $address);
$address = ereg_replace(\"^.*<(.+)>.*$\", \"\\1\", $address);
return $address;
}

function smtp_debug($message)
{
if ($this->debug) {
echo $message;
}
}
}
?>