title: imap_open() cannot open stream using POP3 protocol
body: <p>I cannot retrieve my mail using imap functions but encounter an error saying 'Couldn't open stream'.</p>
  
  <p>The message is<br>
  <b>Warning: imap_open() [function.imap-open]: Couldn't open stream { ... :110 } on line 3</b></p>
  
  <p>I printed the last error as well in my code,<br>
  <b>Cannot connect to Mail: Connection failed to myserver.net,110: Connection timed out</b></p>
  
  <p>I do not understand 'Connection timed out', because the POP3 server works fine with my mail client such as Outlook.</p>
  
  <p>I followed the directions to retrieve my POP3 mails, and I confirmed through web search that I can use imap functions to retrieve mails in a POP3 server.</p>
  
  <p>I also tried '/novalidate-cert' option and checked the username and password.
  But there was no difference.</p>
  
  <p>I attached my code below. It is very mysterious for me,
  can I just connect to the POP3 server?</p>
  
  <pre><code>&lt;?php
  $mbox = imap_open("{mail.myserver.net:110/pop3}", "tester@myserver.net", "passme") or die('LAST ERROR: Cannot connect to Mail: ' . imap_last_error());;
  
  echo "&lt;h1&gt;Mailboxes&lt;/h1&gt;\n";
  $folders = imap_listmailbox($mbox, "{mail.myserver.net:110/pop3}", "*");
  
  if ($folders == false) {
      echo "Call failed&lt;br /&gt;\n";
  } else {
      foreach ($folders as $val) {
          echo $val . "&lt;br /&gt;\n";
      }
  }
  
  echo "&lt;h1&gt;Headers in INBOX&lt;/h1&gt;\n";
  $headers = imap_headers($mbox);
  
  if ($headers == false) {
      echo "Call failed&lt;br /&gt;\n";
  } else {
      foreach ($headers as $val) {
          echo $val . "&lt;br /&gt;\n";
      }
  }
  
  imap_close($mbox);
  ?&gt;
  </code></pre>