What's causing duplicate messages from several senders?

[EncorePS]

Since I reinstalled Outlook 2007 after a clean install of Windows 7 (I
previously had Vista Home Premium), I'm getting duplicate e-mail messages
from several senders. Is there some setting that has been disturbed in the
move from Vista to Windows 7?

 

[Roady [MVP]]

Often this is caused by either a rule or your virus scanner. For details
see;
http://www.howto-outlook.com/faq/duplicates.htm