The best way I can describe this issue is mail will arrive to a user's mailbox successfully but Outlook won't display it without click another folder such as the Sent folder. My own for example does this. I can send myself email from an outside account and it arrives if I login to OWA but in Outlook clients it does not. This is an SBS environment and all are directly connected via LAN.
I confirmed the following: The computers were not set to disable network adapters to conserve power; I made sure Outlook was set to automatically detect the connection state, and I made sure Exchange picks up and delivers the mail as stated above. It looks like a client side problem but ALL of the clients are experiencing the issue. I drilled through Exchange System Manager probing for an option that would make me go AH HA! but I didn't find it. Any help is appreciated, thanks in advance.