outlook mail replication after upgrading zimbra

[aashay]

Hi,

i have upgraded form rhel 4.7 + zcs 5.0.13(OLD server) to ubuntu 8.04 64 bit+zcs 7.1.2(New Server) for testing but when i am starting my outlook then it is downloading all the mails again form the new server. Is there any solution for it so that my ms-outlook does not sync all th emails from server.
Please help me as i want to make it live asap.