Hi all,
New to APM so bear with me 
I have been monitoring 2 identical exchange 2003 servers for a couple of weeks but the last couple of days one server is being reported as application down due to 3 SMTP queue performance counters. I get the below error.
As i understand it, all the performance counters in this template are all obtained by RPC calls but it seems odd that only 3 are having a problem. If i force a test of the components they start working again for a hour then fail again.

Anyone have an idea why this has only just happend?