Outlook 2003 WEBACESS

I have user with two mailboxes and I used Exchange merger to merge the mailboxes .. its goes smoothly but the only know issue is all the emails in the inbox are swiftly transfered but sent folder is as it is.
I had nearly 1.8 GB data which I need to transfer and funny thing I cannot access that data from client computer only at server I can see that.

I have asked user to use webacess to get refrencing of emails through sent folder which is a temp solution.

any suggesstion to fix issue