Master Users, ACL and POP3

Hello, I'm on Dovecot 2.0.9 and I'mfacing issues connecting via POP3 with master user.

I'm using the ACL plugin, so I set up a postlogin script that sets the current user as master user:

#!/bin/sh MASTER_USER=$USER exec "$@"

When I login via IMAP everything seems ok, but when I try via POP3 I get:

-ERR [IN-USE] Couldn't open INBOX: Mailbox doesn't exist: INBOX Connection closed by foreign host.

Any hints? Thanks