Bugger!
It seems that after I’ve finally built a redundant Exchange 2010 cluster with DAG that I needed a reboot on one of the servers (due to some other reconfiguration) – unfortunately I had forgotten the server hadn’t been rebooted since before AVG Business Edition was installed, oops, this appears to interfere with the WinRM service which just wouldn’t work, this meant I couldn’t use anything powered by powershell through the IIS – in other words I had no Exchange Management Console (EMC) or shell commands. The problem wasn’t so much emails as the DAG implementation ensured my other server took care of that with the passive database copy becoming active at the server fail, it was my primary public folder database which had the most problems, it just wouldn’t mount, so a quick scheduled reboot (during the lunch hour) and within 20 minutes (after 2 1/2 hours diagnosis and testing) I had the public folders back, this was also partially affected by the Replication service on the healthy server being stuck in a “stopping” state, I had to kill the process in task manager to fix this and manually start it.
So, what have I learnt today?
Exchange works, now leave it alone!
P.S
somewhere along the line this reboot etc enabled SSL on the pop3 service, this affected a few of our remote users, but I managed to fix that quickly enough once I knew the issue!