For some reason all the sudden all my outlook clients here in the office are trying to connect to Exchange via HTTP. I am running an SBS 2008 w/Exchange 2007. What would cause this?

First make sure that your SBS 2008 server is patched with the latest updates and service packs. There were some issues with Outlook and SBS 2008 about one and half year ago. Then to some possible explanations. By default Outlook is configured this way: Not selected: On fast networks, connect using HTTP first, then connect using TCP/IP Selected: On slow networks, connect using HTTP first, then connect using TCP/IP Slow networks are equal to or below 128 Kbps. So in almost all cases, Outlook will attempt to connect with TCP/IP (MAPI/RPC) first. When not on the corporate network, this attempt will fail, and Outlook will fail over to HTTP (Outlook Anywhere). In your case temporary network problems could trigger off a switch from TCP/IP to HTTP. Another reason for a fail-over occurs after basically these two DNS queries: DNS query: Response - Name Error for the internal Exchange Server name, such as mbx.mycomapany.local. DNS query: Response Success for the external published Outlook Anywhere name, such as mail.mycomany.com In your case, there might be a problem with your internal DNS server. A third reason, your users have selected On fast networks connect using HTTP first. Some users might have done so. In certain hotels, it's the only way to make Outlook Anywhere work, due to something called wild-card synthesis (which requires a longer explanation). But all users, not very likely. First thing I would do: Run Windows Update, or if you have WSUS, make sure it's up to date with its updates and distribution. And in all cases reboot the SBS server. Especially if the SBS server is a bit memory-constrained, some services tend to behave unpredictable.MCTS: Messaging | MCSE: S+M