About a week ago we had an overheating of the server room that caused many of our ESX servers to overheat and power down as well as our EMC Ax4 on which the ESX servers were using in a SAN. Since then we've had two occasions where our Exchange 2003 server will not allow a majority of our users to connect resulting in the "Disconnected" message on their 2003 and 2007 Outlook clients. During this time even though some users are connected they cannot send or receive emails from either outside or inside the enterprise. After a reboot the server comes back up as normal.
In addition, the total Exchange database size is currently 77 GB on Standard Edition although 30 GBs of that is composed of deleted mailboxes, do those still play a part in the restriction that un-mounts your database if it is over 75GB?