Also, HestiaCP doesn’t support Push email. i.e. your users won’t get emails or calendar requestes pushed to their devices automatically like Exchange does via ActiveSync or Gmail does via their protocol. I have investigated this and there is something called “Z-Push” which is open source equivalent of ActiveSync but HestiaCP hasn’t incorporated this in a release and you will have to compile it yourself.
It was long abandoned for over a few years implementing then would require doing a lot of work by our self. It seems to be more active how ever still lacking a lot of things…