Yes.
They are unaware of anything that might be causing a problem or any
changes that might have been made. They are researching to see if any
updates in their Cisco routers might have caused a problem.
One other interesting item to add: This problem occured initially
about two months ago at which time I called the ISP, our corporate IT
and everyone else that I could think of and the best suggestion that I
could get was that there was a DNS or WINS problem. However, since the
exchange server is resolved and all subdirectories except the mailboxes
are accessable, this doesn't seem likely to me. At the time of the
first occurance of the problem, it resolved itself after approximately
3-weeks.
The ISP VPN solution (they call it Transparent LAN Service - TLS) uses
Cisco micro bridge/routers to make the connection back to our central
office. In the process, they inject an IP address into a tracert to
the exchange server from the remote location. These addresses didn't
meet corporate approval and they had me change them via the ISP
subsequent to the first resolution of the problem. After this was
done, the problem reoccured and has been unresolved since. I had the
ISP change one of the address back hoping but it had no affect. It's
as if a router needs to learn a route or more likely port but I can't
imagine why it would take three weeks. Routers and ports are far from
my speciality though so I'm not sure if this even makes sense. Perhaps
more likely in my mind is that an update has been installed somewhere
in the network (either the ISP side or our corporate side) that creates
an incompatibility between exchange and the TLS (VPN).
Enough rambeling, but I hope this casts some more light.
