A user is receiving duplicate emails from some of the users, I checked the message ID to verify that, they are the same. His account is configured on an exchange 2003, outlook is used to check his emails, his pst is stored on the server.
Our corporate email filter is symantec.
Locally on the machine, he has only McAfee anti-virus application.
I checked, he has only one account configured on his PC. and no application scans his in coming emails.
What could be the problem??