PHP基于SMTP协议实现邮件发送实例代码

public function __construct($host,$port,$user,$pass,$debug = false)
{
$this->host = $host;
$this->port = $port;
$this->user = base64_encode($user); //用户名密码一定要使用base64编码才行
$this->pass = base64_encode($pass);
$this->debug = $debug;
//socket连接
$this->sock = fsockopen($this->host,$this->port);
if(!$this->sock){
exit('出错啦');
}
//读取smtp服务返回给我们的数据
$response = fgets($this->sock);
$this->debug($response);
//如果响应中有220返回码，说明我们连接成功了
if(strstr($response,'220') === false){
exit('出错啦');
}
}
//发送SMTP指令，不同指令的返回码可能不同
public function execCommand($cmd,$return_code){
fwrite($this->sock,$cmd);

$response = fgets($this->sock);

//输出调试信息
$this->debug('cmd:'.$cmd .';response:'.$response);
if(strstr($response,$return_code) === false){
return false;
}
return true;
}

public function sendMail($from,$to,$subject,$body){
//detail是邮件的内容，一定要严格按照下面的格式，这是协议规定的
$detail = 'From:'.$from."rn";
$detail .= 'To:'.$to."rn";
$detail .= 'Subject:'.$subject."rn";
$detail .= 'Content-Type: Text/html;'."rn";
$detail .= 'charset=gb2312'."rnrn";
$detail .= $body;
$this->execCommand("HELO ".$this->host."rn",250);
$this->execCommand("AUTH LOGINrn",334);
$this->execCommand($this->user."rn",334);
$this->execCommand($this->pass."rn",235);
$this->execCommand("MAIL FROM:<".$from.">rn",250);
$this->execCommand("RCPT TO:<".$to.">rn",250);
$this->execCommand("DATArn",354);
$this->execCommand($detail."rn.rn",250);
$this->execCommand("QUITrn",221);
}

public function debug($message){
if($this->debug){
echo '

Debug:'.$message . PHP_EOL .'

';
}
}

public function __destruct()
{
fclose($this->sock);
}

}

sendMail($from,$subjet,$body);

Debug:cmd:HELO smtp.163.com ;response:250 OK

Debug:cmd:AUTH LOGIN ;response:334 dXNlcm5hbWU6

Debug:cmd:aXR6aG91anVuYmxvZ0AxNjMuY29t ;response:334 UGFzc3dvcmQ6

Debug:cmd:QzBjSGRRNe32xiNGFYUE5oag== ;response:235 Authentication successful

Debug:cmd:MAIL FROM: ;response:250 Mail OK

Debug:cmd:RCPT TO:380472723@qq.com ;response:250 Mail OK

Debug:cmd:DATA ;response:354 End data with .

Debug:cmd:From:itzhoujunblog@163.com To:380472723@qq.com Subject:我是标题 Content-Type: Text/html; charset=gb2312 hello world . ;response:250 Mail OK queued as smtp11,D8CowACXHE5APdNYCo0hAQ--.19144S2 1490238785

Debug:cmd:QUIT ;response:221 Bye