title: IMAP: Search by a UID range on Exchange server seems to be broken
body: <p>I'm using message UID values to sync an IMAP mailbox with my application. The mail server is Microsoft Exchange Server 2013. <br/>
  According to the IMAP specification, UID numbers should be in a strictly ascending order. However, at times I have found that the search result for a range of UID values returns a number outside the range specified.</p>
  
  <pre><code>=&gt; 'A8 UID SEARCH UID 126095:*'
  &lt;= '* SEARCH 126026'
  &lt;= 'A8 OK SEARCH completed.
  </code></pre>
  
  <p>It looks like a bug to me. Has anyone encountered this issue and is there any way to resolve this?</p>