Outlook 2000 Refresh problem

[HWhite]

I've seen this question before, but no responses that solve my problem.
Several people in my organization have complained lately that items stay in
the Outbox an unusually long amount of time or until they click on another
message or folder in Outlook. Also, incoming messages don't appear unless
you click on another message or folder and then the screen seems to refresh
and show the messages. This is more of an annoyance, but can cause problems
when people are expecting time sensitive e-mails and they think they're not
getting them.

We're running Outlook 2000, service pack 3. Windows XP Pro SP2 with
firewall off by policy. Exchange 2000, service pack 3.

Thanks for any help.

 

[K. Orland]

This is usually an issue with UDP packet handling and is a network router or
firewall issue (not the XP firewall which you have turned off). Has this been
brought to the attention of your network personnel?

 

[HWhite]

I am the network personnel.

There aren't any routers that stand between our Exchange server and our
workstations at this site. I've got a couple ProCurve Switches doing VLANs,
but nothing I can think of that would effect UDP packets. What kind of UDP
packet handling settings should I be looking for?