title: Phpmailer send mail without SMTP authentication
body: <p>I am using Phpmailer for sending emails. Initially it was works fine when I am using SMTP by username and password. If I have tried without SMTP authentication then it returned connection timeout error. Here my code is</p>
  
  <pre><code>&lt;?php
  require 'PHPMailerAutoload.php';
  
  $mail = new PHPMailer;
  $mail-&gt;isSMTP();
  $mail-&gt;SMTPDebug = 2;
  $mail-&gt;Debugoutput = 'html';
  $mail-&gt;Host = "relay-hosting.secureserver.net";
  $mail-&gt;Port = 25;
  $mail-&gt;SMTPAuth = false;
  $mail-&gt;SMTPSecure = false;
  $mail-&gt;setFrom('xxxx@domainname.com', 'First Last');
  $mail-&gt;addAddress("xxxx@domainname.com", "Recepient Name");
  $mail-&gt;addReplyTo("xxxx@domainname.com", "Reply");
  $mail-&gt;isHTML(true);
  
  $mail-&gt;Subject = "Subject Text";
  $mail-&gt;Body = "&lt;i&gt;Mail body in HTML&lt;/i&gt;";
  $mail-&gt;AltBody = "This is the plain text version of the email content";
  
  if(!$mail-&gt;send()) 
  {
      echo "Mailer Error: " . $mail-&gt;ErrorInfo;
  } 
  else 
  {
      echo "Message has been sent successfully";
  }
  
  ?&gt;
  </code></pre>
  
  <p>The returned error is </p>
  
  <blockquote>
    <p>SMTP ERROR: Failed to connect to server: Connection timed out (110)</p>
  </blockquote>
  
  <p>The mail.log file contains</p>
  
  <pre><code>host smtp.secureserver.net[68.178.213.203] refused to talk to
  me: 554 p3plibsmtp03-06.prod.phx3.secureserver.net bizsmtp
  IB105. Connection refused. &lt;ip address&gt; is listed on the
  Exploits Block List (XBL)&lt;http://www.spamhaus.org/query/ip/ip
  address&gt; Please visit http://www.spamhaus.org/xbl/ for
  more information.
  </code></pre>