Mr. Robot types hell-bent on crypto'ing the life out of your data. In 16.5 there's less chance of that happening as one of the new features of interest is the simple, but effective 'From Header Protection/ Modification'. That's not all - there's auto-updating, centralised Outlook Connector settings, an XMPP server (yes, I had to Google it too) and some improvements to Worldclient you've been asking for. Here are my highlights - as usual, you can find the exhaustive version available in the MDaemon Release Notes.