[Dovecot] quota warning

Hi,

Is there a way with dovecot to warn users who are close to reach their quota?

Although I never used it, I think cyrus supports something like that by droping a warning message into the INBOX when delivering a message that brings the total size over a certain percentage.

Would it be feasible to implement something like that with an extra plugin or by changing the quota plugin?

Cheers,

Nicolas