Specifically in reply to the statement: The problem is that if we do not do the sync and replicate, the lotus notes client cannot access the contacts which were entered in iNotes.
Contacts that are entered via iNotes are visible via the following Lotus Notes Client menu option…
Actions > Lotus iNotes > Open Mail File Copy Of Contacts
You can even right click on one of the contacts shown in this view and select “Send a Message.”
However, you really should look into syncing the contacts between local pnab and this iNotes contacts view. It will make life much easier for your users. This can be easily accomplished via Settings/Policies.