I'm testing it in production on a small (58 users) customer on premise "guinea pig" server (with the customer's consent, of course...).
I await feedback from users...
But it will take some time, because here in Italy almost all companies make almost everyone go on holiday during the central weeks of August
Gabriele Maoret - Head of SysAdmins at SERSIS
Currently manages 6 SmarterMail installations (1 in the cloud for SERSIS which provides services to a few hundred third-party email domains + 5 on-premise for customers who prefer to have their mail server in-house)