I have a client who has remote users that are using a DSL VPN to connect to their Exchange 2003 server from several offices all over the state. Ever since they migrated fully from Exchange 5.5 to 2003, and turned off their Exchange 5.5 box, some of the remote users from multiple offices are complaining that Outlook 2003 starts up very very slowly and takes forever to receives e-mails.
These clients DO have Cached Mode enabled, and they do conenct fine otherwise to the Exchange server (ping, network browsing, etc.).
RPC Binding Order is set to TCP/IP. Made sure that their hosts file contains the IP address and DNS name of the new Exchange server.
I have no idea where to look next. I have a suspicion it might have something to do with RPC, but I am not sure.