My name Eric Moyers. I am an Engineer in the Small Business Support Center.
I am sorry to hear that you are experiencing this issue. This is a really strange issue. There are no settings that I think of that would affect Office Exchange, unless there was some ACL's setup that blocked traffic to that server. But I am assuming you have nothing like that setup.
The best thing I can recommend to do, would be to do some packet captures and look at the traffic when this is going on with something like Wireshark. That should give us some insight as to the issue.
If you would like some help doing this, you can call and open a ticket with one of our Small Business Support Centers. When you do this our engineers can work directly with you.
http://www.cisco.com/c/en/us/support/web/tsd-cisco-small-business-support-center-contacts.html
Eric Moyers
.:|:.:|:. CISCO | Cisco Presales Technical Support | Wireless Subject Matter Expert
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