[Dovecot] mail to admin when quota exceeded

[Karolis Žvaigždinas]

We're using Dovecot v1.2.15 LDA/IMAP/POP3+MySQL with quota plugin,
quota_rule per-user size, quota_exceed_message and quota_warning on
storage=90%%.with script.
Everything is working as expected.
But I've been asked to configure it the way, that when a user gets message,
which would make his maildir over quota limit, notification go not only to
sender, but also to postmaster at domain.com.
Browsed wiki, mailinglist archive - couldn't find anything on that.
Is there a way to implement such feature?
And what about possibility to send a message to user, notifying him about
rejected email "from: xxx at yyy.com" with "subj: blah blah" due to full
mailbox? Such messages are small and would not take too much space. Thus the
user would know what he misses, urging him to clean his mailbox.

Thank you in advance.
--
Karolis