I have already asked this in another post (which I can't find now...) and I was told by Tim that it would be implemented in the new version of SmarterMail...
At the moment, however, I don't see it in the new beta
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)