PHP SMTP email sending class, supports SSL connection

<?php
/**
* 邮件发送类
* 支持发送纯文本邮件和HTML格式的邮件，可以多收件人，多抄送，多秘密抄送，带附件(单个或多个附件),支持到服务器的ssl连接
* 需要的php扩展：sockets、Fileinfo和openssl。
* 编码格式是UTF-8，传输编码格式是base64
* @example
* $mail = new MySendMail();
* $mail->setServer("smtp@126.com", "XXXXX@126.com", "XXXXX"); //设置smtp服务器，普通连接方式
* $mail->setServer("smtp.gmail.com", "XXXXX@gmail.com", "XXXXX", 465, true); //设置smtp服务器，到服务器的SSL连接
* $mail->setFrom("XXXXX"); //设置发件人
* $mail->setReceiver("XXXXX"); //设置收件人，多个收件人，调用多次
* $mail->setCc("XXXX"); //设置抄送，多个抄送，调用多次
* $mail->setBcc("XXXXX"); //设置秘密抄送，多个秘密抄送，调用多次
* $mail->addAttachment("XXXX"); //添加附件，多个附件，调用多次
* $mail->setMail("test", "<b>test</b>"); //设置邮件主题、内容
* $mail->sendMail(); //发送
*/
class MySendMail {
    /**
    * @var string 邮件传输代理用户名
    * @access protected
    */
    protected $_userName;
 
    /**
    * @var string 邮件传输代理密码
    * @access protected
    */
    protected $_password;
 
    /**
    * @var string 邮件传输代理服务器地址
    * @access protected
    */
    protected $_sendServer;
 
    /**
    * @var int 邮件传输代理服务器端口
    * @access protected
    */
    protected $_port;
 
    /**
    * @var string 发件人
    * @access protected
    */
    protected $_from;
 
    /**
    * @var array 收件人
    * @access protected
    */
    protected $_to = array();
 
    /**
    * @var array 抄送
    * @access protected
    */
    protected $_cc = array();
 
    /**
    * @var array 秘密抄送
    * @access protected
    */
    protected $_bcc = array();
 
    /**
    * @var string 主题
    * @access protected
    */
    protected $_subject;
 
    /**
    * @var string 邮件正文
    * @access protected
    */
    protected $_body;
 
    /**
    * @var array 附件
    * @access protected
    */
    protected $_attachment = array();
 
    /**
    * @var reource socket资源
    * @access protected
    */
    protected $_socket;
 
    /**
    * @var reource 是否是安全连接
    * @access protected
    */
    protected $_isSecurity;
 
    /**
    * @var string 错误信息
    * @access protected
    */
    protected $_errorMessage;
 
 
    /**
    * 设置邮件传输代理，如果是可以匿名发送有邮件的服务器，只需传递代理服务器地址就行
    * @access public
    * @param string $server 代理服务器的ip或者域名
    * @param string $username 认证账号
    * @param string $password 认证密码
    * @param int $port 代理服务器的端口，smtp默认25号端口
    * @param boolean $isSecurity 到服务器的连接是否为安全连接，默认false
    * @return boolean
    */
    public function setServer($server, $username="", $password="", $port=25, $isSecurity=false) {
        $this->_sendServer = $server;
        $this->_port = $port;
        $this->_isSecurity = $isSecurity;
        $this->_userName = empty($username) ? "" : base64_encode($username);
        $this->_password = empty($password) ? "" : base64_encode($password);
        return true;
    }
 
    /**
    * 设置发件人
    * @access public
    * @param string $from 发件人地址
    * @return boolean
    */
    public function setFrom($from) {
        $this->_from = $from;
        return true;
    }
 
    /**
    * 设置收件人，多个收件人，调用多次.
    * @access public
    * @param string $to 收件人地址
    * @return boolean
    */
    public function setReceiver($to) {
        $this->_to[] = $to;
        return true;
    }
 
    /**
    * 设置抄送，多个抄送，调用多次.
    * @access public
    * @param string $cc 抄送地址
    * @return boolean
    */
    public function setCc($cc) {
        $this->_cc[] = $cc;
        return true;
    }
 
    /**
    * 设置秘密抄送，多个秘密抄送，调用多次
    * @access public
    * @param string $bcc 秘密抄送地址
    * @return boolean
    */
    public function setBcc($bcc) {
        $this->_bcc[] = $bcc;
        return true;
    }
 
    /**
    * 设置邮件附件，多个附件，调用多次
    * @access public
    * @param string $file 文件地址
    * @return boolean
    */
    public function addAttachment($file) {
        if(!file_exists($file)) {
            $this->_errorMessage = "file " . $file . " does not exist.";
            return false;
        }
        $this->_attachment[] = $file;
        return true;
    }
 
    /**
    * 设置邮件信息
    * @access public
    * @param string $body 邮件主题
    * @param string $subject 邮件主体内容，可以是纯文本，也可是是HTML文本
    * @return boolean
    */
    public function setMail($subject, $body) {
        $this->_subject = base64_encode($subject);
        $this->_body = base64_encode($body);
        return true;
    }
 
    /**
    * 发送邮件
    * @access public
    * @return boolean
    */
    public function sendMail() {
        $command = $this->getCommand();
 
        $this->_isSecurity ? $this->socketSecurity() : $this->socket();
         
        foreach ($command as $value) {
            $result = $this->_isSecurity ? $this->sendCommandSecurity($value[0], $value[1]) : $this->sendCommand($value[0], $value[1]);
            if($result) {
                continue;
            }
            else{
                return false;
            }
        }
         
        //其实这里也没必要关闭，smtp命令：QUIT发出之后，服务器就关闭了连接，本地的socket资源会自动释放
        $this->_isSecurity ? $this->closeSecutity() : $this->close();
        return true;
    }
 
    /**
    * 返回错误信息
    * @return string
    */
    public function error(){
        if(!isset($this->_errorMessage)) {
            $this->_errorMessage = "";
        }
        return $this->_errorMessage;
    }
 
    /**
    * 返回mail命令
    * @access protected
    * @return array
    */
    protected function getCommand() {
        $separator = "----=_Part_" . md5($this->_from . time()) . uniqid(); //分隔符
 
        $command = array(
                array("HELO sendmail\r\n", 250)
            );
        if(!empty($this->_userName)){
            $command[] = array("AUTH LOGIN\r\n", 334);
            $command[] = array($this->_userName . "\r\n", 334);
            $command[] = array($this->_password . "\r\n", 235);
        }
 
        //设置发件人
        $command[] = array("MAIL FROM: <" . $this->_from . ">\r\n", 250);
        $header = "FROM: <" . $this->_from . ">\r\n";
 
        //设置收件人
        if(!empty($this->_to)) {
            $count = count($this->_to);
            if($count == 1){
                $command[] = array("RCPT TO: <" . $this->_to[0] . ">\r\n", 250);
                $header .= "TO: <" . $this->_to[0] .">\r\n";
            }
            else{
                for($i=0; $i<$count; $i++){
                    $command[] = array("RCPT TO: <" . $this->_to[$i] . ">\r\n", 250);
                    if($i == 0){
                        $header .= "TO: <" . $this->_to[$i] .">";
                    }
                    elseif($i + 1 == $count){
                        $header .= ",<" . $this->_to[$i] .">\r\n";
                    }
                    else{
                        $header .= ",<" . $this->_to[$i] .">";
                    }
                }
            }
        }
 
        //设置抄送
        if(!empty($this->_cc)) {
            $count = count($this->_cc);
            if($count == 1){
                $command[] = array("RCPT TO: <" . $this->_cc[0] . ">\r\n", 250);
                $header .= "CC: <" . $this->_cc[0] .">\r\n";
            }
            else{
                for($i=0; $i<$count; $i++){
                    $command[] = array("RCPT TO: <" . $this->_cc[$i] . ">\r\n", 250);
                    if($i == 0){
                    $header .= "CC: <" . $this->_cc[$i] .">";
                    }
                    elseif($i + 1 == $count){
                        $header .= ",<" . $this->_cc[$i] .">\r\n";
                    }
                    else{
                        $header .= ",<" . $this->_cc[$i] .">";
                    }
                }
            }
        }
 
        //设置秘密抄送
        if(!empty($this->_bcc)) {
            $count = count($this->_bcc);
            if($count == 1) {
                $command[] = array("RCPT TO: <" . $this->_bcc[0] . ">\r\n", 250);
                $header .= "BCC: <" . $this->_bcc[0] .">\r\n";
            }
            else{
                for($i=0; $i<$count; $i++){
                    $command[] = array("RCPT TO: <" . $this->_bcc[$i] . ">\r\n", 250);
                    if($i == 0){
                    $header .= "BCC: <" . $this->_bcc[$i] .">";
                    }
                    elseif($i + 1 == $count){
                        $header .= ",<" . $this->_bcc[$i] .">\r\n";
                    }
                    else{
                        $header .= ",<" . $this->_bcc[$i] .">";
                    }
                }
            }
        }
 
        //主题
        $header .= "Subject: =?UTF-8?B?" . $this->_subject ."?=\r\n";
        if(isset($this->_attachment)) {
            //含有附件的邮件头需要声明成这个
            $header .= "Content-Type: multipart/mixed;\r\n";
        }
        elseif(false){
            //邮件体含有图片资源的,且包含的图片在邮件内部时声明成这个，如果是引用的远程图片，就不需要了
            $header .= "Content-Type: multipart/related;\r\n";
        }
        else{
            //html或者纯文本的邮件声明成这个
            $header .= "Content-Type: multipart/alternative;\r\n";
        }
 
        //邮件头分隔符
        $header .= "\t" . &#39;boundary="&#39; . $separator . &#39;"&#39;;
 
        $header .= "\r\nMIME-Version: 1.0\r\n";
 
        //这里开始是邮件的body部分，body部分分成几段发送
        $header .= "\r\n--" . $separator . "\r\n";
        $header .= "Content-Type:text/html; charset=utf-8\r\n";
        $header .= "Content-Transfer-Encoding: base64\r\n\r\n";
        $header .= $this->_body . "\r\n";
        $header .= "--" . $separator . "\r\n";
 
        //加入附件
        if(!empty($this->_attachment)){
            $count = count($this->_attachment);
            for($i=0; $i<$count; $i++){
                $header .= "\r\n--" . $separator . "\r\n";
                $header .= "Content-Type: " . $this->getMIMEType($this->_attachment[$i]) . &#39;; name="=?UTF-8?B?&#39; . base64_encode( basename($this->_attachment[$i]) ) . &#39;?="&#39; . "\r\n";
                $header .= "Content-Transfer-Encoding: base64\r\n";
                $header .= &#39;Content-Disposition: attachment; filename="=?UTF-8?B?&#39; . base64_encode( basename($this->_attachment[$i]) ) . &#39;?="&#39; . "\r\n";
                $header .= "\r\n";
                $header .= $this->readFile($this->_attachment[$i]);
                $header .= "\r\n--" . $separator . "\r\n";
            }
        }
 
        //结束邮件数据发送
        $header .= "\r\n.\r\n";
 
 
        $command[] = array("DATA\r\n", 354);
        $command[] = array($header, 250);
        $command[] = array("QUIT\r\n", 221);
         
        return $command;
    }
 
    /**
    * 发送命令
    * @access protected
    * @param string $command 发送到服务器的smtp命令
    * @param int $code 期望服务器返回的响应吗
    * @return boolean
    */
    protected function sendCommand($command, $code) {
        echo &#39;Send command:&#39; . $command . &#39;,expected code:&#39; . $code . &#39;<br />&#39;;
        //发送命令给服务器
        try{
            if(socket_write($this->_socket, $command, strlen($command))){
 
                //当邮件内容分多次发送时，没有$code，服务器没有返回
                if(empty($code))  {
                    return true;
                }
 
                //读取服务器返回
                $data = trim(socket_read($this->_socket, 1024));
                echo &#39;response:&#39; . $data . &#39;<br /><br />&#39;;
 
                if($data) {
                    $pattern = "/^".$code."+?/";
                    if(preg_match($pattern, $data)) {
                        return true;
                    }
                    else{
                        $this->_errorMessage = "Error:" . $data . "|**| command:";
                        return false;
                    }
                }
                else{
                    $this->_errorMessage = "Error:" . socket_strerror(socket_last_error());
                    return false;
                }
            }
            else{
                $this->_errorMessage = "Error:" . socket_strerror(socket_last_error());
                return false;
            }
        }catch(Exception $e) {
            $this->_errorMessage = "Error:" . $e->getMessage();
        }
    }
 
    /**
    * 安全连接发送命令
    * @access protected
    * @param string $command 发送到服务器的smtp命令
    * @param int $code 期望服务器返回的响应吗
    * @return boolean
    */
    protected function sendCommandSecurity($command, $code) {
        echo &#39;Send command:&#39; . $command . &#39;,expected code:&#39; . $code . &#39;<br />&#39;;
        try {
            if(fwrite($this->_socket, $command)){
                //当邮件内容分多次发送时，没有$code，服务器没有返回
                if(empty($code))  {
                    return true;
                }
                //读取服务器返回
                $data = trim(fread($this->_socket, 1024));
                echo &#39;response:&#39; . $data . &#39;<br /><br />&#39;;
 
                if($data) {
                    $pattern = "/^".$code."+?/";
                    if(preg_match($pattern, $data)) {
                        return true;
                    }
                    else{
                        $this->_errorMessage = "Error:" . $data . "|**| command:";
                        return false;
                    }
                }
                else{
                    return false;
                }
            }
            else{
                $this->_errorMessage = "Error: " . $command . " send failed";
                return false;
            }
        }catch(Exception $e) {
            $this->_errorMessage = "Error:" . $e->getMessage();
        }
    } 
 
    /**
    * 读取附件文件内容，返回base64编码后的文件内容
    * @access protected
    * @param string $file 文件
    * @return mixed
    */
    protected function readFile($file) {
        if(file_exists($file)) {
            $file_obj = file_get_contents($file);
            return base64_encode($file_obj);
        }
        else {
            $this->_errorMessage = "file " . $file . " dose not exist";
            return false;
        }
    }
 
    /**
    * 获取附件MIME类型
    * @access protected
    * @param string $file 文件
    * @return mixed
    */
    protected function getMIMEType($file) {
        if(file_exists($file)) {
            $mime = mime_content_type($file);
            /*if(! preg_match("/gif|jpg|png|jpeg/", $mime)){
                $mime = "application/octet-stream";
            }*/
            return $mime;
        }
        else {
            return false;
        }
    }
 
    /**
    * 建立到服务器的网络连接
    * @access protected
    * @return boolean
    */
    protected function socket() {
        //创建socket资源
        $this->_socket = socket_create(AF_INET, SOCK_STREAM, getprotobyname(&#39;tcp&#39;));
         
        if(!$this->_socket) {
            $this->_errorMessage = socket_strerror(socket_last_error());
            return false;
        }
 
        socket_set_block($this->_socket);//设置阻塞模式
 
        //连接服务器
        if(!socket_connect($this->_socket, $this->_sendServer, $this->_port)) {
            $this->_errorMessage = socket_strerror(socket_last_error());
            return false;
        }
        $str = socket_read($this->_socket, 1024);
        if(!preg_match("/220+?/", $str)){
            $this->_errorMessage = $str;
            return false;
        }
         
        return true;
    }
 
    /**
    * 建立到服务器的SSL网络连接
    * @access protected
    * @return boolean
    */
    protected function socketSecurity() {
        $remoteAddr = "tcp://" . $this->_sendServer . ":" . $this->_port;
        $this->_socket = stream_socket_client($remoteAddr, $errno, $errstr, 30);
        if(!$this->_socket){
            $this->_errorMessage = $errstr;
            return false;
        }
 
        //设置加密连接，默认是ssl，如果需要tls连接，可以查看php手册stream_socket_enable_crypto函数的解释
        stream_socket_enable_crypto($this->_socket, true, STREAM_CRYPTO_METHOD_SSLv23_CLIENT);
 
        stream_set_blocking($this->_socket, 1); //设置阻塞模式
        $str = fread($this->_socket, 1024);
        if(!preg_match("/220+?/", $str)){
            $this->_errorMessage = $str;
            return false;
        }
 
        return true;
    }
 
    /**
    * 关闭socket
    * @access protected
    * @return boolean
    */
    protected function close() {
        if(isset($this->_socket) && is_object($this->_socket)) {
            $this->_socket->close();
            return true;
        }
        $this->_errorMessage = "No resource can to be close";
        return false;
    }
 
    /**
    * 关闭安全socket
    * @access protected
    * @return boolean
    */
    protected function closeSecutity() {
        if(isset($this->_socket) && is_object($this->_socket)) {
            stream_socket_shutdown($this->_socket, STREAM_SHUT_WR);
            return true;
        }
        $this->_errorMessage = "No resource can to be close";
        return false;
    }
}