[Dovecot] LDAP quota groups

[ian+dovecot at comtek.co.uk]

Is there any way to have a per-LDAP-group quota? The OpenLDAP folk's 
suggestions are to hack the source for an overlay (ideal, but it looks 
somewhat involved) or to do it at the application (Dovecot).

I've added an LDAP userattr 'quotaMegaBytes' which is great for allowing 
me to override the server's default quota on a per-user basis, but 
ideally I'd be able to override the quota only for people who are member 
of a certain LDAP group.

Perhaps I could override it for IMAP sessions with a postlogin script, 
but I can't see any way to apply it to deliver.

Thanks for any suggestions,

Ian