[Dovecot] LMTP Proxy not logging users' IP

Hi All, is there any way to enable logging of users' IP address in dovecot director host? It actually logs only: Sep 14 07:32:29 mailgw-lb dovecot: lmtp(17615): Connect from xx.xx.xx.xx Sep 14 07:32:29 mailgw-lb dovecot: lmtp(17615): Disconnect from xx.xx.xx.xx: Client quit

Thanks Luca