Some of the user have the strange problem when they receive email.
Sometimes they will receive double same email(Same sender, same
subject, same receive time, etc.)
After check with some staff PC, I found the problem relate to Office
version.
All of the problem user is not using office 2003 version, some is
using office 2000 and Office XP.
But all of the user is using Microsoft Outlook 2003. After I upgrade
one of the problem user office from XP to 2003, the problem is
fixed.
What's the happen of the outlook without same version office will be
receive double email?
What type of mail server?
Are the double messages always from the same sender, or is just
random messages that are doubled? Do they all have attachments?

Our server is Exchange 07, the problem is not regulation, it's random
message, some have attachments, some hadn't.

Ok, knowing it's Exchange:

Is it only messages internal to Exchange, messages from the Internet or both?

Either way, really, I'd turn message tracking way up in Exchange and wait for
the next event and see where the two messages might have come from, in
other words, is it an Exchange issue or is it an Outlook issue.

--
f.h.
Microsoft Outlook MVP