A few clients (5) have reported to me the following issue:

First thing in the morning when they power on their machine and then login
the first thing they do is open outlook. Their complaint is that outlook
takes a while to finish the initial sync. For the rest of the day the other
syncs go quickly.

Here is the layout of this network:

outlook 2003 SP2 cache mode on windows xp sp2 with an exchange 2003 sp2
environment.
We have 5 remote offices each connected to headquarters’ office via a
dedicated t1 line where the single exchange server exists.
Each remote office has 3 windows 2003 SP2 2 of which are DC and also global
catalog.

I have since:

Verified that there are not routing issues or any flaws on the T1 line. (no
errors)
Monitored for any event id errors on all servers and the clients’ pcs. (all
systems error free)
Defragged the clients pcs
Updated the antivirus software on clients’ pc and specified that the
antivirus plug-in be removed from outlook.
Even ran Microsoft exchange tools to ensure that there are no bottlenecks.

I have even asked the clients to give the machines upon bootup and logon
about 10 minutes before they use it.

Still the issue is still occurring.

Any suggestions?