@Henk, these are part of [pseudo] standard Lua "extensions", and just included by MiOS. You'd need to persue the package owners to see if they'd add the SSL/TLS (LuaSec) stuff into it, since they're from the Lua community itself.
Internally, I believe they look for values being set against the User vars prior to emitting an AUTH Header. If there are not present (as distinct from "blank") then it'll work just fine.
Technically, the pieces to build SSL-SMTP are there, but it would be a lot of work to get it going (or to understand how to better hook LuaSec into the LuaSocket framework)... likely more time than anyone here has to spare.
In many reguards, it would be simpler to petition MCV to add native SMTP setup to the Local Vera box (since Linux has all the requisite bits already), and then just send Email locally through it. Unfortunately, that would add complexity to the install (etc) that most people probably aren't prepared for.