Almost every 4 hours I need to rebote the exchange server due to the Active directory is inactive. I try to reconnect but that doesn't work, then I perform a pwrdwn restart and that is making it active again. The error in the event viewer for DNS = A zone transfer for the secondary zone rrsdom.com was refused by the master DNS server at 172.16.0.5, They ask me to check the zone transfer and see if this is enabled. It is.

I would ask this in the Windows Forums as it relates to DNS. http://social.technet.microsoft.com/Forums/en/category/windowsserver/