Problem with importing contacts into Active Directory using csvde

I am importing a whole bunch of contacts into Active Directory

I am getting a problem when trying to email them however.  The issue I have worked out is that it isn't creating a legacyExchangeDN entry

when you create a contact manually, this gets created, but my csvde import isn't

any ideas why?

here are my import headings which work fine

DN,objectClass,displayName,mailNickname,givenName,sn,Department,mail,Title,telephoneNumber,targetAddress,proxyAddresses,Company,Description