Is it possible to export Domino Directory to a format that can be read by Postfix on Suse Linux?

Hi

I was thinking of making my own blacklist that would be checked for the existence of my Users on Domino while the message is still on the postfix instead of having the postfix send it to domino and domino replying with the usual “User not listed on domino Directory”

The purpose of this is that I have many incoming spam that is answered by domino so I want to lighten the traffic on it.

I also want this file/blacklist to be updated daily from the domino directory as we have new users almost daily.

Thanks