title: mu4e does not list all messages in INBOX
body: <p>I have installed and configured <code>mu</code> and <code>mu4e</code> as explained in the <a href="http://www.djcbsoftware.nl/code/mu/mu4e/" rel="nofollow noreferrer">manual</a> (newest version on emacs 24.3.1). My <code>mu4e</code> config contains:  </p>
  
  <pre class="lang-lisp prettyprint-override"><code>(setq mu4e-maildir "~/Maildir/mail_user_de")
  
  (setq mu4e-drafts-folder "/Drafts")
  (setq mu4e-sent-folder   "/Sent")
  (setq mu4e-trash-folder  "/Trash")
  </code></pre>
  
  <p>These folders exist and each contains three subfolders: <code>cur</code>, <code>new</code> and <code>tmp</code>. When I fire up <code>mu4e</code> it says:  </p>
  
  <blockquote>
    <p>[mu4e] Started mu4e with 4023 messages in store</p>
  </blockquote>
  
  <p>however, when I enter the <code>INBOX</code> folder, there is no mail listed. On the other hand, when I enter the <em>last 7 days</em> bookmark, all emails from the last seven days are listed.  </p>
  
  <p>My assumption is, that <code>mu4e</code> does not care for emails which have been downloaded <strong>outside</strong> of emacs because  </p>
  
  <ol>
  <li>When I update (calling <code>offlineimap</code> and <code>mu index</code>) within <code>mu4e</code> the email are sorted correctly into the <code>INBOX</code></li>
  <li>When I update <strong>outside</strong> of emacs, the mails are listed in the bookmark but <strong>not</strong> in the <code>INBOX</code> until they are marked read <strong>outside of <code>mu4e</code></strong>. If this happens outside of <code>mu4e</code> they will not show up in the <code>INBOX</code>, otherwise they will suddenly appear (flagged read) in the <code>INBOX</code>.  </li>
  </ol>
  
  <p>Obviously I don't like this. I would prefer if all mails, independent whether they were downloaded from within <code>mu4e</code> or directly in a terminal, show up in the <code>INBOX</code>. Is this a bug or a feature (which, so I hope, can be disabled)?</p>