From last couple of weeks I am getting connection problem with my in-house company exchange server 5.5 running on windows 2003. It has been working fine from last 5 years. but from few weeks it is loosing connection with other outlook clients. I have to restart my exchange server to make it work. This happens few times in a week. It looses connection somewhere between 7PM to 8AM as when I come in office. I find this problem, while it leave office it works fine.
We have not installed any updates or software since last more than 2 years.
What could be the reason for stop working?