I'm already using it on my 2 "guinea pig" servers (small servers with less than 100 users each...).
They are working fine so far, but they were updated just a few hours ago, so I don't have a reliable statistic.
I will keep you updated if I receive any reports of malfunctions...
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)