[Dovecot] LDAP Authentication - Home Directory Creation

How does everyone handle this case?

Users are authenticated by LDAP, and do not have accounts on the IMAP/dovecot server. When a new user is added to LDAP, the home directory (/home/newuser) needs to be created on the IMAP/dovecot server so dovecot can create the mail directories inside it (/home/newuser/mail/).

Obviously I can come up with a few custom solutions, utilizing cron, but I feel like there's a cleaner solution out there.

Thanks!