Am I correct in understanding that on the wired network that some hosts do work and some hosts do not work? In that case one question would be whether there is any pattern in the addresses that do work and those that do not work (is it perhaps one part of the subnet range that works and another part that does not)?
Another question would be whether the hosts that do not reach the outlook server can ping the address of the server?
One thing that might help us figure out the issue would be to post the output of a traceroute to the outlook server from a host that does work and then the output of a traceroute from a host that does not work.
HTH
Rick
HTH
Rick