title: How to fetch Inbox only with attachments using mail-listener2?
body: <p>I am new to mail-listener. I am able to fetch gmail inbox along with attachments but my requirement is to fetch inbox only. With attachments using mail-listener:</p>
  
  <pre class="lang-js prettyprint-override"><code>var mailListener = new MailListener({
      username: "xxxx@gmail.com",
      password: "xxx",
      host: "imap.gmail.com",
      port: 993, // imap port
      tls: true,
      //ssl:true,
      connTimeout: 10000, // Default by node-imap
      authTimeout: 5000, // Default by node-imap,
      debug: console.log, // Or your custom function with only one   incoming argument. Default: null
      tlsOptions: { rejectUnauthorized: false },
      mailbox: "INBOX", // mailbox to monitor
      //searchFilter: ["UNSEEN", "FLAGGED"], // the search filter being used after an IDLE notification has been retrieved
      markSeen: true, // all fetched email willbe marked as seen and not fetched next time
      fetchUnreadOnStart: true, // use it only if you want to get all unread email on lib start. Default is `false`,
      mailParserOptions: {streamAttachments: true}, // options to be passed to mailParser lib.
      attachments: true, // download attachments as they are encountered to the project directory
      attachmentOptions: { directory: "attachments/" } // specify a   download directory for attachments
  });
  </code></pre>
  
  <p>Instead mailbox : "INBOX" I want something like mailbox : "INBOX ONLY ATTACHMENTS"
  or searchfilter : "HAS ATTACHMENTS"</p>