I've seen/tested HiveMail throughout the time Chen has been developing it. I guess I was his little guinea pig a couple of times. I was lucky to have that advantage, as the HiveMail site is located on my server (shared with TubeDogg).
I'll be helping with HiveMail whenever I'm needed though. So if you try and get a hold of support, you just may be hearing back from me
HiveMail is the best mail script I've ever seen or used for that matter! I love it!