I have Windows 2003 Server terminal servers in several sites, with Outlook 2003 as email clients. Server is Exchange 2010, located in my main site. The remote site terminal servers are connected through WAN links that are 5 Mbps connections, with generally very low usage compared to capacity.
Outlook works properly for 2 - 3 days for the remote site users, but then, their connections start to drop, and they see "Outlook is trying to connect the the exchange server ..." systray messages, and they lose their email. Can't see their inbox contents, though sometimes the tree gets populated. The only fix is to reboot the terminal server.
Similar terminal servers at the main site do not experience this.
The backstory is that I recently migrated users from Exchange2003 to Exchange2010. On exchange 2003 we never had this problem.
What is going on here?