[Dovecot] Automatic mail script?

Hello!

I am setting up a Dovecot mailserver for around 2000 people with: sendmail + dovecot + squirrelmail + spamassassin and some plugins.

I have the Imap quota working in mboxes with this quota commands:

plugin { # 10MB quota limit quota = dirsize:storage=10240 }

It worked good in Squirrelmail, but the person that only use some imap program (outlook, eudora) don't get the info when theirs account will be full of mail.

So can someone give me a good script for a automatic mail. I want to send a mail to a user when they are nearly exceeded their limits, so they can start cleaning theirs account.

Are this possible or how should I solve this problem?

/Andreas