[Dovecot] Maildirsize file isn't updated after doing POP

Hello,

I have a problem about updating Maildirsize file. It seems that the Maildirsize file is not updated after user does POP mail from his maildir. I do not want to use any quota limitation in Dovecot. I only want Dovevot to update the Maildirsize file after user retrieves his mail. The Maildirsize file is created by Postfix. Would it be possible to do like this? How can I configure it? Could you please advice me?

The Dovecot version is 1.0.7.

Thank you very much, Nitass