In my experience s(which include work with HP (Compaq)) they point to purchasing a 3rd party product.
Technically you can use the migration tool as a connector which is what many people have done with Exchange 5.5. On the exchange site they talk of a notes connector for exchange 2000, but 2003 exchange has no post.
So my question is why do you need an exchange connector? Suppose you thought of this scope, a corporate intranet can have Domino and Exchange co-exist without the need of a connector. I can see the point of people wanting to have calendars be updated, but you will have limits between the 2 platforms anyway.
My client handles doclinks by making file attachments in the format of a NDL. You click it and it will do the same as a notes document link. My client also has intranet URLs for those applications which can be access through their intranet.
HTH -- Cheers
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