title: Maildrop: Filter mail by Date: header
body: <p>I'm using getmail + maildrop + mutt + msmtp chain with messages stored in Maildir. Very big inbox bothers me, so i wanted to organize mail by date like that:</p>
  
  <pre><code>Maildir
  |-2010.11-&gt;all messages with "Date: *, * Nov 2010 *"
  |-2010.12-&gt;same as above...
  |-2011.01
  `-2011.02
  </code></pre>
  
  <p>I've googled much and read about mailfilter language, but still it is hard for me to write such filter. Maildrop's mailing list archives has almost nothing on this (as far as i scanned through it). There is some semi-solution on <a href="https://unix.stackexchange.com/questions/3092/organize-email-by-date-using-procmail-or-maildrop">https://unix.stackexchange.com/questions/3092/organize-email-by-date-using-procmail-or-maildrop</a>, but i don't like it, because i want to use "Date:" header and i want to sort by month like "YEAR.MONTH" in digits.
  Any help, thoughts, links, materials will be appreciated.</p>